JP4244493B2 - Recording / playback device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording / reproducing apparatus capable of recording cue data and reproducing the data using the cue data.
[0002]
[Prior art]
For example, data such as video is recorded using a tape drive device using a magnetic tape as a storage medium. In this case, the tape drive device performs data recording and reproduction by sequential access to the magnetic tape.
[0003]
[Problems to be solved by the invention]
Incidentally, since the magnetic tape can take a large-capacity configuration as a recording medium, it is suitable for recording large-capacity data such as video data. However, as described above, recording and reproduction are performed by a sequential access operation. Therefore, depending on the recording position on the magnetic tape, it takes a long time to access the file to be reproduced.
Thus, for example, it is known that cue data corresponding to a file to be recorded on a magnetic tape is recorded by a hard disk device or the like and the data is reproduced without impairing real-time performance.
For this reason, it is desired to set the capacity of the cue data according to the recording position of the file on the magnetic tape so that the hard disk device can be used efficiently, and the cue reproduction data is not interrupted. Yes.
[0004]
[Means for Solving the Problems]
In order to solve such a problem, the present invention has a plurality of tape cassettes that store magnetic tapes in which a plurality of recording areas of a predetermined unit are formed, and selects and transports the plurality of tape cassettes. Changer means, tape drive means for loading a tape cassette transported by the changer means, and recording / reproducing with respect to the magnetic tape stored in the tape cassette, and at least the tape A buffer area for recording or reproducing data in the drive means, and a cue data area for recording cue data when reproducing the file corresponding to the file recorded on the magnetic tape Hard disk drive means, and tape cassette transport time by the changer means , On the basis of the distance of the load / unload area and files that have been created on the magnetic tape, constituting the recording and reproducing apparatus includes a cue data capacity setting means for setting the capacity of the cue data.
[0005]
Further, a tape drive means for loading a tape cassette storing a magnetic tape in which a plurality of recording areas of a predetermined unit are stored, and performing recording and reproduction with respect to the magnetic tape stored in the tape cassette. And at least a buffer area for recording and reproducing data in the tape drive means, and a head for recording cue data corresponding to the file recorded on the magnetic tape and reproducing the file. A hard disk drive means having a start data area; a start data recording control means capable of recording start data in the start data area with a predetermined capacity; and an end of the recorded area on the magnetic tape. When the predetermined position of the recordable area is reached, the second load / unload area is set at the predetermined position. Based on the distance between the load / unload area creation means that can be formed, the second load / unload area formed on the magnetic tape, and the file recorded on the magnetic tape, When the second load / unload area is created by the cue data capacity setting means for obtaining the data capacity and the load / unload area creation means, the cue data is recorded from the cue data already recorded. A recording / reproducing apparatus is provided with data erasing means for erasing data corresponding to the difference from the capacity obtained by the data capacity setting means.
[0006]
Further, a tape drive means capable of loading a tape cassette storing a magnetic tape in which a plurality of recording areas of a predetermined unit are stored, and recording and reproducing the magnetic tape stored in the tape cassette. And at least a buffer area for recording and reproducing data in the tape drive means, and a head for recording cue data corresponding to the file recorded on the magnetic tape and reproducing the file. Hard disk drive means having a start data area, and a start data capacity setting means for setting the capacity of the start data based on the distance between the load / unload area created on the magnetic tape and the file The recording / reproducing apparatus is configured.
[0007]
According to the present invention, the capacity of the cue data is obtained based on the transport time of the tape cassette by the changer means and the distance between the load / unload area created on the magnetic tape and the file. The cueing data of the capacity corresponding to the distance from the loading / unloading area and the transport time of the tape cassette can be recorded.
[0008]
In addition, for cue data corresponding to a file that is recorded near the second load / unload area and has good accessibility after loading, by deleting part of the cue data as necessary, The minimum necessary cue data can be recorded.
[0009]
Furthermore, since it is possible to record the cueing data having a capacity corresponding to the moving time from the loading of the magnetic tape to the file recording position, during the movement to the desired file recording position after loading, Cue data corresponding to the file can be read out.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in the following order.
1. System description
1-1. External view, block diagram
1-2. Data storage device block diagram
1-3. Block diagram of the tape drive
1-4. Data flow during recording and playback
1-5. Magnetic tape layout
1-6. The size of the division that supports fragmentation
1-7. Changer unit configuration example
1-8. Hard disk part
2. File system
2-1. Configuration example of host computer device
2-2. Command example output from the driver section
2-3. Processing on the computer side
2-4. Data storage device processing
3. Data storage level
3-1. Recording of BOF data
3-2. Preservation level
3-3. Save level update
3-4. File life cycle
4). Loading / unloading magnetic tape
4-1. Load / unload after EOD area
4-2. Load / unload in device area # 1
4-3. Load / unload process
4-4. Connecting data
5). BOF data optimization
[0011]
1. System description
  1-1. External view, block diagram

  FIG. 1 is an external view showing the entire data storage system of the present embodiment. In this figure, the computer device 41 is constituted by a personal computer, for example, as a host computer, and a keyboard.120By doing so, it is possible to perform a required operation. Further, an operation image for an interface formed by the computer device 41 (for example, a window format using a GUI (Graphic User Interface) or the like) is displayed on the monitor device 100. Therefore, the user can monitor100Various operations of the computer device 41 can be performed according to the operation image displayed on the screen.
[0012]
The operation image displayed on the monitor device 100 is, for example, a hard disk device, a floppy disk drive device, or a CD (Compact Disc) or a CD-ROM (Compact Disc Read Only Memory) built in the computer device 41, for example. A disk drive device that reads data recorded on a disk-shaped recording medium is iconified. Therefore, when the user refers to the contents of data stored in the hard disk device, a window corresponding to the hard disk device is displayed by selecting an icon corresponding to the hard disk device by a required operation. In the window, icons corresponding to various files and application programs stored in the hard disk device are displayed.
As a result, the user can visually grasp the presence / absence of a file by looking at the window, and can shift to various file selection operations and operations for executing application software.
[0013]
In addition, the data storage device 1 of the present embodiment is connected to the computer device 41 via an interface means such as SCSI (Small Computer Serious Interface). That is, the data storage device 1 is configured as an external storage device connected to the computer device 41.
[0014]
FIG. 2 is a block diagram illustrating a configuration example of the computer device 41 and the data storage device 1.
The data storage device 1 includes a controller unit 2 having, for example, a SCSI interface and a control unit that performs various controls of the data storage device 1 as data input / output means for the computer device 41.
The hard disk unit 3 records data supplied from the computer device 41 (for example, a file such as a video) on, for example, a magnetic tape (not shown) loaded in the tape drive unit 4 or the magnetic A buffer area for reproducing data recorded on the tape, an area for recording management information of a file recorded on the magnetic tape, or a data storage area for cueing used for reproduction, An area for recording connection data corresponding to the case where data reading is interrupted during access is formed.
In some cases, data transferred from the computer device 41 is recorded only on the hard disk unit 3 or only on the magnetic tape.
[0015]
The tape drive unit 4 is capable of recording / reproducing data using a magnetic tape stored in a tape cassette loaded by the changer unit 5 as a recording medium. As will be described later, a recording area in units called divisions is formed on the magnetic tape.
For example, when recording data, the data stored in the buffer area of the hard disk unit 3 is recorded in a required division, and when reproducing data, the data recorded in the division is stored in the hard disk unit 3. Output to the buffer area.
The changer unit 5 includes, for example, rack means that can store 20 tape cassettes in the present embodiment. The changer unit 5 selects a specific tape cassette for recording / reproducing from the 20 tape cassettes stored in the rack means and conveys the selected tape cassette to the tape drive unit 4. However, in the data storage device 1, for example, magnetic tapes stored in 20 tape cassettes are handled as one magnetic tape, not as independent recording media.
That is, the data storage device 1 is configured as a device including a recording medium having a capacity corresponding to, for example, 20 magnetic tapes provided in the hard disk unit 3 and the changer unit 5.
[0016]
The computer device 41 includes at least application software 42 (hereinafter referred to as an application), an operation / file system 43 (hereinafter referred to as a file system), and a hard disk device (not shown) provided as a storage unit of the computer device 41. A driver unit 44 serving as software for driving and controlling the data storage device 1 is stored.
In this figure, only the main part is shown and omitted, but the computer device 41 includes, for example, a disk-shaped recording medium (floppy disk, CD-ROM, etc.) drive device, and a CPU (Central Processing Unit) and the like, and can be used as a general computer device.
[0017]
By the way, a window screen corresponding to the data storage device 1 constructed as a GUI by the computer device 41 and displayed on the monitor device 100 is as shown in FIG. 3, for example.
The window 101 is, for example, the entire computer device 41. For example, an icon 102 indicating a floppy disk drive, an icon 103 indicating a hard disk drive, or icons 104 and 105 indicating setting holders including operation items for performing various settings. , And an icon 106 corresponding to the data storage device 1 of the present embodiment.
In the window 110, icons 111, 112, and 113 corresponding to the contents of the data storage device 1 are shown as windows disclosed when the icon 106 is selected. As described above, in the data storage apparatus 1, a plurality of (20 in the present embodiment) tape cassettes are configured as one recording medium. Therefore, the icons 111, 112, and 113 are the hard disk unit 3 and the tape cassette unit. And is formed for each file corresponding to, for example, a movie stored in the hard disk unit 3 or the magnetic tape of the data storage device 1.
In other words, the data storage device 1 causes the computer device 41 to recognize it as one drive device having a large capacity by the hard disk unit 3 or the tape cassette, for example, like a hard disk drive device.
[0018]
1-2. Block diagram of drive device
FIG. 4 is a block diagram for explaining a configuration example of the data storage device 1. In this figure, the controller unit 2 is particularly explained.
The controller unit 2 includes an interface unit (hereinafter referred to as I / F unit) 6, a buffer controller unit 7, an I / F buffer 8, and an interface unit 9 in the data path during recording or reproduction.
[0019]
The I / F unit 6 is arranged between the computer device 41 and is configured as an input / output stage when the data storage device 1 and the computer device 41 perform data communication at the time of recording / reproduction or the like.
The buffer controller 7 unit is constituted by, for example, direct memory accesses 7 a and 7 b and controls data transfer between the I / F unit 6 and the I / F unit 9. The I / F buffer 8 is configured as a buffer memory of the buffer controller unit 7.
The I / F unit 9 is configured as an interface unit used for data transfer between the hard disk unit 3 and the tape drive unit 4 in the data storage device 1.
When data transferred from the computer device 41 is recorded on the hard disk unit 3 or data reproduced by the tape drive unit 4 is transferred to the computer device 41, data transfer is performed via the I / F unit 9. For example, when data stored in the hard disk unit 3 is supplied to the tape drive unit 4, data transfer may be performed directly between the hard disk unit 3 and the tape drive unit 4.
[0020]
For example, at the time of recording, data transferred from the computer device 41 is supplied to the direct memory access 7 a via the I / F unit 6 and stored in the I / F buffer 8. The data stored in the I / F buffer 8 is read by the direct memory access 7 b and supplied to the hard disk unit 3 through the I / F unit 9.
For example, at the time of reproduction, data read from the hard disk unit 3 or the tape drive unit 4 is supplied to the direct memory access 7 b via the I / F unit 9 and stored in the I / F buffer 8. The data stored in the I / F buffer 8 is read by the direct memory access 7 a and transferred to the computer apparatus 41 via the I / F unit 6.
[0021]
The control unit 11 is composed of, for example, a microcomputer, and controls the respective parts of the controller unit 2 via the bus 14 to perform operation control of the entire data storage device 1 when performing recording or reproduction, for example. Have been to do.
In addition, the control unit 11 controls the changer unit 5 via the I / F unit 9. That is, based on various commands corresponding to recording or reproduction supplied from the computer device 41 via the I / F unit 6, a predetermined tape cassette containing a magnetic tape for recording or reproducing data is stored in the tape. It also controls the drive unit 4 to convey. In this case, the control is based on the tape cassette usage (management information) stored in the hard disk unit 3 together with the information supplied from the computer device 41.
[0022]
The ROM 12 and RAM 13 store data used for various processes when the control unit 11 performs control such as data recording or reproduction. For example, the ROM 12 stores constants used for control. The RAM 13 is also used as a work memory.
The ROM 12 and the RAM 13 are also used as an internal memory of the microcomputer that constitutes the control unit 11.
[0023]
1-3. Block diagram of the tape streamer section
FIG. 5 is a block diagram illustrating a configuration example of the tape drive unit 4.
The data path during recording or reproduction in the tape drive unit 4 includes an I / F unit 20, a controller unit 21, a group buffer 22, and an RF processing unit 23, and further at a predetermined position around the rotary drum 24. , Reproducing heads 25A, 25B, 25C and recording heads 26A, 26B are provided.
The I / F unit 20 is configured as a data input / output stage for the controller unit 2.
[0024]
  The controller unit 21 includes a direct memory access 21a and a signal processor 21b, for example, and controls data transfer between the I / F unit 20 and the RF processing unit 23. In addition, the signal processor 21b is configured to perform a required error correction process on recorded data and reproduced data, for example.
  The RF processing unit 23 generates a recording signal to be recorded on the magnetic tape 40 and generates reproduction data based on the reproduction RF signal read from the magnetic tape 40.
  During recording, the RF processing unit 23 performs processing such as amplification and recording equalization on the recording data supplied from the controller unit 21, generates a recording signal, and supplies the recording signal to the recording heads 26A and 26B. As a result, data is recorded on the magnetic tape 40 from the recording heads 26A and 26B.
  At the time of reproduction, the recorded data on the magnetic tape 40 is transferred to the reproduction head.25A, 25BThe RF reproduction signal read out by the above is supplied as a reproduction output, and reproduction equalization, reproduction clock generation, binarization, decoding (for example, Viterbi decoding) and the like are performed.
[0025]
The mechanical controller 27 applies a required drive voltage to each drive motor so as to rotationally drive a drum motor, a capstan motor, a reel motor, a loading motor, an eject motor, etc. (not shown). .
The mechanical controller 27 drives each motor based on the control from the servo controller 28. The servo controller 28 controls the rotational speed of each motor to execute normal recording / reproduction running, tape running during high-speed reproduction, fast-forwarding, tape running during rewinding, and the like.
The EEP-ROM 32 stores constants used by the servo controller 28 for servo control of each motor.
[0026]
The control unit 29 is configured by, for example, a microcomputer, and the tape drive unit 4 is based on various commands supplied from the computer device 41 through the controller unit 2 via the bus 35 when performing recording or reproduction, for example. Each part is controlled. For example, when data is recorded, the tape cassette loaded by the changer unit 5 is fast-forwarded to the recording position on the magnetic tape 40 and the recording head 26A, 26B is supplied with recording data. During reproduction, fast-forwarding to the reproduction position on the magnetic tape 40 of the loaded tape cassette is executed.
[0027]
Further, the ROM 30 and the RAM 31 store data used for various processes when the control unit 29 performs control such as data recording or reproduction, similarly to the ROM 12 and the RAM 13 shown as the configuration of the controller unit 2 in FIG. The That is, for example, the flash ROM 30 stores constants used for control, and the RAM 31 is used as a work memory.
[0028]
1-4. Data flow during recording
Here, according to the schematic diagram of FIG. 6, a series of data flow in the data storage apparatus 1 in the case of recording will be described in correspondence with the passage of time.
As shown in FIG. 6A, when recording data is transferred from the computer device 41 to the data storage device 1, it is first stored in the I / F buffer 8 (path (1) in FIG. 4). Next, the data stored in the I / F buffer 8 is transferred to the hard disk unit 3 as shown in FIG. 6B (path (2) in FIG. 4). Thereby, the recording data is stored in, for example, a buffer area of the hard disk unit 3. The transition of the data transfer shown in FIG. 6A to FIG. 6B is based on the capacity of the I / F buffer 8 and is performed when a predetermined amount of data is accumulated in the I / F buffer 8. .
Next, when the data stored in the hard disk unit 3 is transferred to the tape drive unit 4 and recorded on the magnetic tape 40, it is as shown in FIG. It is stored in the group buffer 22 (path (3) in FIG. 4). As shown in FIG. 6D, the data read from the group buffer 22 in units of groups is recorded on the magnetic tape 40 (path (4) in FIG. 4). The transition of the data transfer shown in FIG. 6C to FIG. 6D is executed when data of, for example, one group unit is accumulated in the group buffer 22 due to the capacity of the group buffer 22.
Note that the data transfer transition (path (3) in FIG. 4) shown in FIGS. 6B to 6C can be executed by a “COPY” command in the SCSI interface, for example. However, when an interface means having no command corresponding to the “COPY” command, such as ATA (AT Attachment), is applied, data transfer is performed via the I / F buffer 8. Become.
[0029]
Therefore, the transition shown in FIG. 6B to FIG. 6C is performed at intervals based on the size of the buffer area of the hard disk unit 3, and FIG. 6A to FIG. 6B and FIG. The transition shown in (c) to FIG. 6 (d) is performed in a relatively shorter period than the transition shown in FIG. 6 (b) to FIG. 6 (c).
[0030]
1-5. Magnetic tape layout
FIG. 7 is a schematic diagram for explaining the layout of the magnetic tape 40 wound and accommodated on a required reel in the tape cassette. In the present embodiment, it is assumed that the recording area of one magnetic tape 40 has a capacity of 50 GB (gigabytes), for example.
FIG. 7A schematically shows one magnetic tape 40.
A leader tape (not shown) is physically located at the head of the first portion of the magnetic tape 40, and a device area is provided as a region for loading / unloading the magnetic tape 40 next. . The head of the device area is a physical tape head position PBOT (Physical Beginning of Tape). In this specification, “loading” refers to the operation from when a tape cassette is loaded into the tape drive unit 4 until the magnetic tape stored in the tape cassette is pulled out and the recorded data can be read out. The unloading is an operation from storing the magnetic tape 40 in the tape cassette to ejecting the tape cassette from the tape drive unit 4.
[0031]
Subsequent to the device area, a recording area in which data is recorded is formed. For example, the recording area is divided into minimum units for performing required recording and reproduction called division. Each division shown in the figure is managed by being given a division number as indicated by divisions # 1, # 2, # 3. In the present embodiment, as will be described later, for example, a total of 400 divisions from division # 1 to division # 400 are formed. In the present embodiment, the end of the last division which is division # 400 is the final position PEOT (Physical End of Tape) of the physical tape.
[0032]
Although not shown in this figure, when recording is performed on the magnetic tape 40 and the recording position reaches a predetermined position, for example, the central portion (for example, division # 200), the first is shown. A device area # 2 that is a second load / unload area is formed with respect to the device area # 1 that is a load / unload area. Then, after the device area # 2 is formed, the load / unload operation is performed by the device area # 2. The load / unload operation using this device area # 2 will be described later.
[0033]
For example, the data recording unit in one division shown in FIG. 7B can be divided into fixed length units called groups shown in FIG. 7C. As shown, one division is formed by 112 groups. For example, data transferred from the computer device 41 is supplied to the tape drive unit 4 in units of groups via the hard disk unit 3.
One group corresponds to a data amount of 20 frames. The breakdown of these 20 frames is, for example, 18 data frames and 2 parity frames. Then, as shown in FIG. 7D, one frame is formed by two tracks. In this case, two tracks forming one frame are adjacent to plus azimuth and minus azimuth tracks. Therefore, one group is formed by 40 tracks.
[0034]
Further, the data structure for one track shown in FIG. 7D is shown in FIGS. 8A and 8B. FIG. 8A shows a data structure in units of blocks. One block is formed of a 1-byte SYNC data area A1, a 6-byte ID area A2 used for searching, a parity area A3 for error correction consisting of 2 bytes for ID data, and a 64-byte data area A4. The
[0035]
The data for one track shown in FIG. 8B is formed by all 471 blocks, and one track is provided with margin areas A11 and A19 for four blocks at both ends as shown in the figure. ATF areas A12 and A18 for tracking control are provided in front of the margin A19. Further, parity areas A13 and A17 are provided behind the AFT area A12 and before the ATF area A18. As these parity areas A13 and A17, an area of 32 blocks is provided.
[0036]
In addition, an ATF area A15 is provided in the middle of one track, and areas for five blocks are provided as these ATF areas A13, A15, and A18. Data areas A14 and A16 for 192 blocks are provided between the parity area A13 and the ATF area A15 and between the ATF area A15 and the parity area A17, respectively. Therefore, all data areas (A14 and A16) in one track occupy 192 × 2 = 384 blocks out of all 471 blocks.
The tracks are physically recorded on the magnetic tape 40 as shown in FIG. 8C. As described above, 40 tracks (= 20 frames) form one group.
[0037]
Next, the ID area A2 shown in FIG. 8A will be described with reference to FIG. FIG. 9 shows the data structure of the ID area A2. This ID area A2 is composed of a 9-bit physical block address (A21) followed by a 39-bit ID information area (ID Information Area) A22. It consists of areas.
[0038]
As described above, since all data areas (A14 and A16) in one track are composed of 384 blocks, the number of physical block addresses A21 included in these all data areas is also 384.
These 384 physical block addresses A21 are given address values so as to be incremented from 0 to 383 in decimal notation in order from the physical block address A21 located at the head of one track, for example.
Thereby, for example, the information in the ID information area A22 included in the data area in one track can be appropriately handled by the recording / reproducing apparatus side. Here, as the data size of the ID information area A22 included in the data area in one track,
39 (Bit) x 384 (Block) = 14976 (Bit) = 1872 (Byte)
As required by the above, it becomes 1872 bytes.
[0039]
In the ID information area A22, various ID area information corresponding to the data structure of the magnetic tape 40 is stored so as to be applied according to a predetermined rule. As the ID area information, at least an area ID indicating which recording area the frame belongs to, for example, a device area or a division is stored in the present embodiment. Therefore, the tape drive unit 4 reads the area ID when the magnetic tape 40 is loaded after the tape cassette is loaded, so that the position of the magnetic tape 40 (device area # 1, device area # 2, or load / load) is read. Whether the data is loaded in the unload area LUA) can be identified.
In consideration of enabling reliable reading of the ID area information by the tape streamer drive 10, the same type of ID area information is recorded a plurality of times according to a predetermined rule for each track.
[0040]
1-6. Changer section
FIG. 10 is a diagram schematically showing the layout of each tape cassette loaded in the rack means of the changer unit 5 and the magnetic tape 40 wound in each tape cassette.
For example, a total of 20 tape cassettes from #A to #T are loaded. Further, the device area is omitted in the layout of the magnetic tapes 40 (at) loaded in each tape cassette.
As described above, for example, 400 divisions are formed on the magnetic tape 40. Therefore, when looking at the magnetic tape 40a of the tape cassette #A, it can be seen that divisions "A001" to "A400" are formed as symbols shown in parentheses.
Similarly, "B001" to "B400" for the magnetic tape 40b, "C001" to "C400" for the magnetic tape 40c, "R001" to "R400" for the magnetic tape 40r, and "S001" for the magnetic tape 40s. ”To“ S400 ”, and 400 divisions are formed on the magnetic tape 40T, such as“ T001 ”to“ T400 ”.
[0041]
In the data storage apparatus 1, all divisions formed on the magnetic tapes (at) of these 20 tape cassettes are managed as recording areas formed continuously. Accordingly, the division numbers recognized by the data storage apparatus 1 are # 1 to # 8000, which are serial numbers corresponding to 8000 (400 × 20) divisions formed on all magnetic tapes (at). Is done. That is, the magnetic tape having 8000 divisions from # 1 to # 8000 is as shown in FIG. 11, for example. In the data storage device 1, as shown in this figure, the magnetic tapes 40a to 40t are handled as a single magnetic tape. Therefore, as described above, if the storage capacity of one magnetic tape 40 (at) to be wound in each tape cassette is 50 GB (gigabyte), for example, it has a storage capacity of 1 TB (terabyte). The tape-shaped recording medium is provided in the data storage device 1. Therefore, the data storage device 1 can perform recording for about 370 hours when the transfer rate of video data is 6 Mbps, for example. Hereinafter, when the magnetic tapes 40a to 40t are simply indicated as one magnetic tape, they are also simply referred to as the magnetic tape 40.
[0042]
For example, when the data recorded in the division number # 6801 is read by constructing such a division structure, the control unit 11 of the data storage device 1 attaches the tape cassette #R to the changer unit 5 as a tape. The drive unit 4 is instructed to load, and the tape drive unit 4 is instructed to access the second division from the top of the magnetic tape 40r. As a result, the tape drive unit 4 can read and output the data recorded in the division of division number # 6801.
[0043]
1-7. Hard disk part
FIG. 12 is a diagram for explaining a configuration example of a recording area formed in the hard disk unit 3 provided in the data storage device 1.
The buffer area E1 is a buffer used when recording data transferred from the data storage device 1 from the computer device 41, or when transferring data read from the tape drive unit 4 from the data storage device 1 to the computer device 41. Configured as a ring area.
The file information table area E2 is a table area in which management information relating to files recorded in the data storage device 1 (for example, video data units such as movies) is stored.
The division access map E3 is an area in which information such as the usage status of divisions (1 to 8000) formed on the magnetic tape 40 is stored.
[0044]
A BOF (Beginning of File) area E4 is an area in which, for example, a head portion of a file is recorded as cue data (BOF data). For example, when reading a file, first, BOF data is read, and the tape drive unit 4 can access a required division of the magnetic tape 40 while transferring the BOF data to the computer device 41. become. As a result, it is possible to perform data reproduction almost in real time in accordance with a reproduction command supplied from the computer device 41 without being affected by a relatively time-consuming access operation of the magnetic tape 40.
Note that after the tape drive unit 4 accesses the required division of the magnetic tape 40, the data is read from the magnetic tape 40 instead of the BOF data, and the data is transferred to the computer device 41.
[0045]
In the connection data area E5, for example, when a situation occurs in which one file is recorded in a state of being fragmented over a plurality of magnetic tapes, the connection data area E5 records the connection data required for the period of replacing the tape cassette. It is an area to keep. Thus, for example, even when a tape cassette needs to be replaced during playback of one file, the connection data is read and transferred to the computer device 41 while the tape cassette is being replaced by the changer unit 5. As a result, the real-time property can be maintained without interruption of the reproduction data.
[0046]
  FIG. 13 is a diagram illustrating a configuration example of the buffer area E1.
  This buffer area E1 is formed by areas Bu0 to Bu79 each corresponding to the capacity of one division formed on the magnetic tape 40. That is, data corresponding to 80 divisions can be stored in the buffer area E1. For example, when the area Bu is configured with 125 MB, the buffer area E1 has a capacity of 10 GB (gigabytes). In this case, for example, when converted to time assuming MPEG2, video data for about 2 hours can be buffered..
When recording data, for example, assuming that the buffer area E1 is unused, the data transferred from the computer apparatus 41 to the data storage apparatus 1 is area Bu0, area Bu1, area Bu2,... In addition, it is buffered for each capacity corresponding to the division. When all the data of the file to be recorded is stored in the buffer area E1, buffering ends at that time. Note that data transfer from the buffer area E1 to the tape drive unit 4 is performed at a required timing as necessary while buffering is being performed.
[0047]
When recording using the buffer area E1 is performed in this way, for example, during the recording of one file, it is necessary to replace the tape cassette by the changer unit 5, and once the recording to the magnetic tape 40 is performed. Even if the recording operation is interrupted, the data transferred from the computer device 41 is accumulated in the buffer area E1 in real time. Therefore, after the replacement of the tape cassette is completed, in the buffer area E1, the data immediately before the recording operation is interrupted is read from the area Bu and stored in the magnetic tape 40, whereby the real-time recording operation on the magnetic tape 40 is performed. Can be realized.
Also, when reproducing the recorded data, the head portion of the file stored in the buffer area E1 is read while the tape drive unit 4 and the changer unit 5 are accessing the magnetic tape 40, It can be transferred to the computer device 41.
[0048]
If the capacity of the file transferred from the computer device 41 to the data storage device 1 is larger than the buffer area E1, buffering using the area Bu0, area Bu1, area Bu2,..., Area Bu79 ends. Then, the subsequently transferred data is buffered by overwriting the area Bu0, the area Bu1, the area Bu2,... Again, for example. That is, regardless of the amount of data transferred from the computer device 41, buffering is continuously performed while the file is being recorded.
In this case, for example, a portion corresponding to the head of the file is deleted, but the heading data corresponding to the file may be stored in the heading data area as necessary. Further, when overwriting is performed in the buffer area E1, data recorded in the overwritten division is recorded on the magnetic tape 40 in advance.
[0049]
FIG. 14 is a diagram illustrating a configuration example of the file information table area E2.
Various information for each file recorded in the data storage device 1 is recorded in the file information table area E2.
For example, the file ID is information for selecting a specific file as the file identifier information when the data storage device 1 performs, for example, reproduction or update of the file.
The attribute information is formed by the file storage level and the playback rate. The file storage level is information indicating the state of the file based on information recorded in the file information table area E2 described below. The reproduction rate is information indicating a data transfer rate.
The access count information is information indicating the number of times the file has been accessed, and is incremented each time the file is reproduced, for example.
The write end time information is information indicating the time when the recording of the file ends.
The last access date / time information indicates the date and time when the file was last accessed.
The start division number indicates from which division of the magnetic tape 40 the file is started. In the present embodiment, for example, any division number from # 1 to # 8000 is indicated.
The file size information indicates the recording capacity of the file.
[0050]
As described above, information related to the file recorded in the data storage device 1 is recorded in the file information table area E2, but attribute information, access count information, write end time, last access date information, and start division number information. The storage level is set based on the file size information.
[0051]
FIG. 15 is a diagram illustrating a configuration example of the division access map E3.
The division access map E3 indicates the usage status of each division corresponding to the file recorded on the magnetic tape 40. That is, the data storage device 1 can grasp the usage status of each division by the status code corresponding to the division.
As the status code, for example, “0002h” corresponding to division # 1 indicates that data following division # 1 is stored in division # 2. That is, the order in which the recording data is recorded in the division is indicated. Therefore, for example, when playing a file, if the division number corresponding to the head of the file to be played is designated by the start division number information shown in the file information table area E2 based on an instruction from the computer device 41. Thereafter, the desired division can be accessed sequentially with reference to the division access map E3.
Further, “FFFFh” as the status code indicates that the division is the last division of the file. That is, in the division access map E3, there are as many status codes “FFFFh” as the number of recorded files.
That is, in the example shown in FIG. 15, it is shown that data forming a certain file is recorded in the order of division 5 → division 6 → division 7 → division 1 → division 2 → division 3. Yes.
[0052]
For example, when the division is not used, “0000h” is set, which indicates that the division is not currently used and corresponds to a space area or a blank area. The space area is an area where a file has been recorded in the past but is not used at this time because, for example, the recorded data is deleted. The blank area is an area in the magnetic tape 40 where no file has been recorded in the past. For example, when recording is performed from the first division of the magnetic tape 40, the end of the recorded area, Alternatively, a continuous unused area from the division at the end of the last space area to the division at the end of the area that can be recorded on the magnetic tape 40 is shown. Therefore, a division in which data is recorded even once is not treated as a blank area even if the recorded data is erased and becomes an unused area.
[0053]
In the present embodiment, divisions from # 1 to # 8000 are formed, and information on each division includes information from division numbers # 1 to # 8000, but the division access map E3 includes As the division number # 0, for example, an offset amount up to the blank area is indicated. Therefore, when the tape drive unit 4 accesses the blank area, the blank area is searched based on the content indicated by the status code of the division number “0” in the division access map E3.
In this manner, the space area and the blank area are distinguished from each other so that the unused area can be used efficiently, the file fragmentation can be suppressed, and the magnetic tape 40 can be used on average.
[0054]
In this way, the usage status of all divisions is managed by the division access map E3. Therefore, when the data storage device 1 receives an instruction for recording, reproduction, etc. from the computer device 41, the data storage device 1 refers to the division access map E3 before actually performing an access operation to the magnetic tape by the tape drive unit 4. It is possible to grasp the usage status of the division.
[0055]
1-8. The size of the division that supports fragmentation
By the way, assuming that the data storage device 1 is used to record and play back a relatively large amount of video data such as a movie, for example, real-time performance is required when recording and playing back data. Become.
For this reason, when one file is fragmented, for example, when the reproduction of the first fragment is completed, the file is moved to the second fragment, the third fragment, and so on, and then reproduced again after the moving operation. Will start.
[0056]
FIG. 16 is a schematic diagram showing an example in which a fragmented file is played. In addition, although the fragment | piece of a 2nd piece exists in the magnetic tape of the same tape cassette or the magnetic tape of the other tape cassette distribute | arranged to the rack means of the changer part 5, in this figure, the latter As an example.
As shown in FIG. 16A, one file is divided and the first piece is recorded on the magnetic tape 40f, the second piece is recorded on the magnetic tape 40l, and the third piece is recorded on the magnetic tape 40p. ing. When playing back a file that has been divided across multiple magnetic tapes in this way, the changer unit 5 first replaces the tape cassette, and the tape drive unit 4 further changes to the division in which the fragments are recorded by fast-forwarding or the like. Access. In this transition, as shown in FIG. 16B, after the first piece is read from the magnetic tape 40f, the moving time t1 from the first piece to the second piece (changer unit 5, tape drive). The second fragment is read from the magnetic tape 40l through the operation of the section 4). When the reading of the second fragment is completed, the third fragment is read from the magnetic tape 40p after the movement time t2.
[0057]
The data (fragment) read from the magnetic tape 40 in the transition shown in FIG. 16 (b) is temporarily stored in the buffer area E1 of the hard disk unit 3 as described above, and read from this buffer area E1. Transferred to computer device 41. However, in this case, since the speed at which the data read from the magnetic tape 40 is reproduced by the computer device 41 is slower than the speed at which the data is read from the magnetic tape 40, there is a time difference between the read time and the reproduction time. become. Therefore, as the playback video, as shown in FIG. 16 (c), the fragments are connected to form a video that maintains real-time characteristics.
[0058]
Thus, even when moving from the first fragment to the second fragment, the data read from the tape drive unit 4 and stored in the buffer area E1 of the hard disk unit 3 is continuously transferred to the computer device 41. Thus, the real time property of the reproduction data can be maintained.
Therefore, in order to guarantee the real-time property of this playback data,
Read time from magnetic tape-video playback time> = time to move to fragment
It is sufficient to satisfy the condition. That is, it is only necessary to store data corresponding to a capacity that is longer than the time required to move between fragments in the area Bu of the buffer area E1.
[0059]
For example, if the size of the division is 128 Mbytes, for example, video data having a transfer rate of 6 Mbps as MPEG2, for example, the playback time is
128 × 8/6 = 171sec
It becomes. For example, assuming that the transfer rate of data read from the magnetic tape 40 in the tape drive unit 4 is, for example, 48 Mbps, and converting this into playback time,
128 x 8/48 = 21 sec
It becomes. That is, data that requires 171 seconds as the reproduction time can be read out in 21 seconds by the tape drive unit 4. Therefore, the time of 150 seconds, which is the difference, can be used as the movement time from fragment to fragment.
[0060]
As described above, the data storage device 1 is configured to perform recording or reproduction with respect to the magnetic tape 40 by using the buffer area E1 formed in the hard disk unit 4 as a buffer means. That is, since it is configured as a recording / reproducing apparatus that combines the high-speed accessibility of the hard disk unit 4 and the large capacity of the magnetic tape 40, it is suitable for recording and reproducing video data that requires, for example, large capacity and real-time performance. It becomes a thing.
[0061]
2. File system
2-1. Configuration example of host computer device
The data storage device 1 is made to recognize the computer device 41 as a random access device such as a hard disk device, but is actually configured as a tape streamer drive device having a plurality of tape cassettes. Recording and playback operations are executed by sequential access. Therefore, the driver unit that causes the computer device 41 to drive (record and reproduce) the data storage device 1 converts a random access command issued by the application program or file system of the computer device 41 into a sequential access command. . That is, the computer device 41 can handle the data storage device as a random access device similar to a hard disk device, for example.
[0062]
FIG. 17 is a diagram illustrating a configuration example of the computer device 41 when the operation of the data storage device 1 is executed.
As shown in the figure, the computer device 41 has an application 42 that is software for executing recording and reproduction of image data in units of files, for example, by a user, and recording and reproduction on a hard disk, for example. An operation / file system 43 (hereinafter referred to as a file system) is provided that performs recording and reproduction by designating an LBA (Logical Block Address) of a cluster (for example, 64 KB) as a unit for performing the recording. By using these application software 42 and file system 43, recording and reproduction by random access can be executed for a random access device such as a hard disk device.
[0063]
In the present embodiment, in addition to the application software 42 and the file system 43, a driver unit 44 is provided as software for causing the data storage device 1 to execute recording and playback operations. Includes an LBA management table for converting random access into sequential access.
The LBA management table stores various information corresponding to each file recorded in the data storage device 1. FIG. 17 shows information corresponding to the file “F001”, for example. In this LBA management table, the Index information is a sequential value in the LBA management table. The CLBA information indicates an address assigned in units of clusters, and the Size information indicates the number of clusters corresponding to the CLBA information address.
[0064]
When a random access write command is supplied from the file system 43, the driver unit 44 first notifies the data storage device 1 of the file name. Then, the order of the write commands corresponding to the file to be recorded and the LBA at that time are associated with each other and stored as Index information and CLBA information in the LBA management table. In addition, information “F001” is stored as file ID information so that a table corresponding to a file can be specified.
[0065]
In the example illustrated in FIG. 17, the cluster whose index information is “0” is “# 10”, and the size is “1”. Similarly, clusters with Index information “1” and “3” are respectively “# 15” and “# 18”, and the size is “1”. In addition, the cluster whose index information is “2” is “# 18”, and the size is “3”.
The driver unit 44 stores such information in the LBA management table in response to a write command supplied from the file system 43, and further sequentially to the data storage device 1 in the order shown in the Index information. Send a write command. For example, when CLBA # 10 is “a”, # 15 is “b”, and # 18 is “c” “d” “e”, the data storage device 1 uses “a” “b” on the magnetic tape 40. Files are recorded in a sequence of “c”, “d”, “e”, and “f”.
[0066]
When data is recorded on the magnetic tape 40 in this way, CLBA information corresponding to the file “F001” in the LBA management table is as shown in FIG. As shown in the figure, when the CLBA information corresponding to the file “F001” is viewed, the arrangement is random, but in the LBA management table corresponding to the file “F001”, the CLBA information (a, b, c, d, By managing only e, f, and so on, it becomes possible to handle these data as sequential.
That is, the information recorded in the LBA management table of the driver unit 44 corresponds to the sequence of data constituting the file recorded in the data storage device 1. Therefore, when a random access read command is supplied from the file system 43 in order to read the file “F001” from the data storage device 1, the driver unit 44 is requested from the file system 43 based on the LBA management table. It is possible to specify the LBA corresponding to the data recorded by the write command when the file “F001” is recorded. When a file is recorded in the data storage device 1, each piece of information related to the file is recorded in the file information table E2.
[0067]
Further, since the data storage device 1 is configured to read in units of files, when a plurality of files are recorded, the LBA management table is recorded in the data storage device 1 as shown in FIG. As shown in the files “F001”, “F002”, “F003”, “F004”..., Information corresponding to each file is recorded. Therefore, when reproducing a file recorded in the data storage device 1, the driver unit 44 first transmits file ID information to the data storage device 1. Thereafter, sequential read commands are transmitted. For example, when reproducing the file “F001”, if “# 10”, “# 15”, “# 18”, and “# 30” are transmitted as read commands, the data storage device 1 stores “a” and “b” recorded on the magnetic tape 40. “C” “d” “e” “f” is read out in sequence.
[0068]
2-2. Command example output from the driver section
In this way, in order to realize sequential recording and reproduction in units of files with respect to the data storage device 1, the driver unit 44 defines, for example, a SCSI command as described below. Note that #N corresponds to the file ID and corresponds to “F001”, “F002”, “F003”, “F004”, and the like.
Create File #N: Start writing a new file.
Close File #N: Ends writing and reading.
Open File #N: Start reading the recorded file
Delete File #N: Erasing recorded data
Send Real Time Speed (in Mbps)
: Notification of playback rate to guarantee real-time performance
Set Realtime Mode ON
: Turn on real-time mode
Space: Fast forward
[0069]
2-3. Processing computer equipment
FIG. 20 is a diagram for explaining the transition of processing executed on the computer device 41 side when causing the data storage device 1 to execute data recording based on the various commands described above.
First, the application 42 issues a write command “Write File # F001” for executing the recording of the file # F001. The application 42 issues a command based on, for example, a required operation by the user. When the application 42 issues a write command, the file system 43 issues a write command specifying an LBA that is a cluster unit. The driver unit 44 to which the write command is supplied from the file system 43 first outputs a “Create File # F001” command to start writing a new file to the data storage device 1. Note that a “Send Real Time Speed” command is output to guarantee the continuity of the recorded data as necessary. Thereafter, the driver unit 44 outputs a write command in LB units.
The driver unit 44 sequentially writes the LBA supplied from the file system 43 in the LBA management table. That is, after the “Create File # F001” command is issued, the recording data is sequentially transferred to the data storage device 1, and the LB (Logical) of the data transferred to the data storage device 1 is stored in the LBA management table. Block) will be recorded.
[0070]
When ending the recording, the driver unit 44 issues a “Close File # F001” command to the data storage device 1. As a result, the data storage apparatus 1 ends the data recording operation.
As described above, when the data storage device 1 performs recording, the driver unit 44 designates a file to the data storage device 1 and instructs the recording start, and instructs the recording end. "Close File # F001" command is issued. The processing steps related to data recording in the meantime are managed by the LBA management table of the driver unit 44.
[0071]
FIG. 21 is a diagram for explaining the transition of processing executed on the computer device 41 side based on the various commands described above when the data storage device 1 executes data reproduction. FIG. 21 shows an example in which file # F001 is reproduced from the beginning.
When the application 42 issues a read command “Read File # F001” for executing reproduction of the file # F001, the file system 43 issues a read command designating an LBA (# 10) that is a cluster unit.
Then, the driver unit 44 to which the read command is supplied from the file system 43 first outputs an “Open File # F001” command for starting reading of the file to the data storage device 1. Thereby, the data storage device 1 refers to the file information table area E2 and executes an operation of accessing and reading the file # F001 recorded on the magnetic tape 40, for example. Thereafter, the driver unit 44 outputs a read command in units of LB, and when the reading is terminated, the driver unit 44 issues a “Close File # F001” command to the data storage device 1.
[0072]
Further, when the reproduction is executed from the middle of the file # F001, for example, as shown in FIG.
Also in this case, when the application 42 issues a read command “Read File # F001” for causing the file # F001 to be read, the file system 43 issues a read command designating the LBA (# 15) as a cluster unit. .
Then, the driver unit 44 to which the read command is supplied from the file system 43 first outputs an “Open File # F001” command for starting reading of the file to the data storage device 1 and further realizes real-time reproduction. In addition, a “Set Realtime Mode ON” command is output.
As a result, the data storage device 1 recognizes the file to be played and shifts to a state where playback can be performed. After accessing the head of the file # F001, the data “b” (CLBA in the LBA management table) In order to execute the reproduction from the information # 15), a “Space” command is issued to rapidly feed the magnetic tape to the data “b”. Thereafter, as in the case described above, the driver unit 44 outputs a read command in units of LB, and issues a “Close File # F001” command to end reproduction.
[0073]
FIG. 23 is a flowchart showing the processing steps in the computer apparatus 41 when the data storage apparatus 1 executes data recording as shown in FIG.
First, the application 42 requests the file system 43 to execute data recording (S001). Upon receiving the data write execution request, the file system 43 issues a random access write LBA to the driver unit 44 (S002). The driver unit 44 sequentially registers the LBA supplied from the file system 43 in the LBA management table (S003), and the driver unit 44 issues a sequential write command to the data storage device 1 (S004). ).
As a result, the data storage device 1 can record data transferred from the computer device 41 by sequential access.
[0074]
FIG. 24 is a flowchart showing processing steps in the computer device 41 when the reproduction of data recorded in the data storage device 1 is executed as shown in FIGS.
When the application 42 requests the file system 43 to execute data reproduction (S101), the file system 43 issues a random access read LBA to the driver unit 44 (S102). Based on the LBA supplied from the file system 43, the driver unit 44 searches the CLBA information recorded in the LBA management table corresponding to the file # F001 to be read, and searches the data to be read (S103). ). Further, the driver unit 44 issues a sequential read command corresponding to the data to be read to the data storage device 1 (S104).
[0075]
As described above, the computer device 41 includes the driver unit 44 and converts the random access command into the sequential access command, thereby causing the data storage device 1 to execute data recording or data reproduction by sequential access. Will be able to.
[0076]
2-4. Drive-side processing
In the data storage device 1, recording and reproduction operations are executed based on sequential commands supplied from the driver unit 44 of the computer device 41.
FIG. 25 is a flowchart for explaining an example of processing steps executed by, for example, the control unit 11 when data transferred from the computer device 41 is recorded on the magnetic tape 40 of the data storage device 1.
When the data storage device 1 shifts to the operating state, it waits for a command from the driver unit 44 (S201). When it is determined that a command (Create File) for instructing the start of data recording is supplied from the driver unit 44, necessary information is stored in the file information table E2 (FIG. 14) (S202), and the computer device 41 Is transferred to the buffer area E1 (FIG. 13) (S203).
Then, the division for recording data on the magnetic tape 40 is selected (S204). Here, it is determined whether or not the connection data is necessary (S205). If it is determined that the connection data is necessary, the necessary connection data is recorded in the connection data area E5 (S206).
[0077]
As described above, after the processing steps related to the connection data, the data stored in the buffer area E1 is stored on the magnetic tape 40 selected in step S203 based on the sequential write command supplied from the driver unit 44 as needed. The process proceeds to recording in the division (S207). That is, in this step S207, first, the changer unit 5 selects a tape cassette, and the tape drive unit 4 is controlled to move to a predetermined division in the selected tape cassette, and then the recording operation is performed. .
When the process proceeds to the data recording process, it is determined whether or not the “Close File” command for instructing the end of the recording is supplied from the driver unit 44 (S208). If it is determined that the “Close File” command is not supplied, the recording is continued. In this case, it is determined whether or not there is free space in the selected division (S209). ). If it is determined that there is free space, the process returns to step S207 to continue the recording operation. However, if it is determined that there is no free space, the process returns to step S204 to select a division and continue the recording operation.
If it is determined that the “Close File” command has been supplied, it is determined whether or not data to be recorded on the magnetic tape 40 remains in the buffer area E1 (S210), and it is determined that no data remains. Assumes that the recording of the data transferred from the computer device 41 has been completed, and terminates the recording operation (S211). However, if it is determined in step S210 that there is still data to be recorded on the magnetic tape 40, the process proceeds to step S209, where data is recorded based on the free capacity of the selected division.
[0078]
The processing step for selecting a division shown in step S203 will be described later.
Further, in the flowchart shown in this figure, a series of flows when recording on the magnetic tape 40 via the buffer area E1 of the hard disk unit 3 has been described. For example, data transferred from the computer device 41 is buffer area E1. In other cases, the data recorded in the buffer area E1 may be treated as the recording data of the data storage device 1 and not recorded on the magnetic tape 40.
[0079]
Next, an example of processing steps executed by the control unit 11 when reproducing data recorded on the magnetic tape 40 of the data storage device 1 will be described with reference to the flowchart of FIG.
Similarly to the case described with the flowchart at the time of recording, when the data storage device 1 shifts to the operating state, it waits for a command from the driver unit 44 (S301). When it is determined that the “Open File” command for instructing the start of data reproduction is supplied from the driver unit 44, the file ID specified by the “Open File” command is detected (S302), and the detected file is detected. The file information table E2 is searched based on the ID, and the start division of the file to be reproduced is specified (S303).
When the start division is specified, first, a process of accessing the start division, that is, the beginning of the file is started (S304). In this case, first, the tape cassette is selected by the changer unit 5 and the tape drive unit 4 is controlled to move to a predetermined division in the tape cassette loaded by the changer unit 5. After that, the reading operation from the magnetic tape 40 is executed. Here, it is determined whether or not the “Space” command is supplied from the driver unit 44 (S305), and when it is determined that the “Space” command is supplied, that is, when playback is performed from the middle of the file, The file is moved to a position where reproduction is started in the file, and an offset corresponding to the “Space” command is obtained (S306).
[0080]
When the reproduction start position is specified in step S304 or step S306, the process proceeds to a reproduction operation of reading data from the position on the magnetic tape 40 (S307). The data read from the magnetic tape 40 is once stored in the buffer area E1, then read from the buffer area E1 and transferred to the data storage device 1.
When the data reproduction operation is executed in this way, it is determined whether or not the data recorded in the division has been read (S308). If it is determined that the data has not been read yet, the process proceeds to step S307. Continue reading return data. If it is determined that the recording of the data recorded in the division has been completed, referring to the division access map E3 (FIG. 15) (S309), there is the next division in which the file data is recorded. Is determined (S310). If it is determined that there is a next division, the division is accessed (S311), and the process returns to step S307 to continue reading data recorded in the next division. If it is determined in step S310 that there is no next division, the reproduction operation is terminated (S312).
In step S307 and subsequent steps, when the recorded data is being played back, if a “Close” command for instructing the end of playback is supplied from the driver unit 44, the playback operation is finished at that point.
[0081]
Thus, by providing the computer device 41 with the driver unit 44 corresponding to the data storage device 1, the random access command issued from the application 42 and the file system 43 in the computer device 41 is converted into a sequential access command by the driver unit 44. The data can be converted and output to the data storage device 1.
Accordingly, the provision of the driver unit 44 allows the computer apparatus 41 to recognize the data storage apparatus 1 as a random access device and handle it in the same manner as an external storage apparatus such as a general hard disk apparatus.
[0082]
Further, the LBA managed by the file system 43 of the computer device 41 and the file management (file information table E2, division access map E3) in the data storage device 1 are individually performed, and correspondence is achieved by command conversion by the driver unit 44. ing. Therefore, the file system 43 of the computer apparatus 41 issues a command as a random access device to the data storage apparatus 1, and the data storage apparatus 1 performs data communication with the computer apparatus 41 as a sequential access device. That is, it is not necessary for the data storage device 1 and the computer device 41 to be aware of the processing steps for command conversion in the driver unit 44.
In addition, the data storage device 1 can independently determine whether to record data to the hard disk unit 4 or the magnetic tape 40 instead of an instruction from the file system 43 of the computer device 41. The data storage device 1 can independently perform the most efficient recording.
[0083]
3. Data storage level
3-1, BOF data recording and playback path
For example, when the access distance on the magnetic tape is long, the tape drive unit 4 requires a relatively long access time. For this reason, the real-time property of video data may be impaired, for example.
Therefore, the data storage device 1 includes the hard disk unit 3 as a buffer means at the time of data recording. For example, as a BOF data of a predetermined capacity at the time of data recording, a part of the data that is the head portion of the file is stored in the BOF data area E4 It can be recorded.
[0084]
FIG. 27 is a schematic diagram for explaining a path when data transferred from the computer apparatus 41 is recorded in the data storage apparatus 1.
The file transferred from the computer device 41 is temporarily stored in the required area Bu in the buffer area E1 as indicated by the path K1, and then from the area Bu as indicated by the path K2 at the required timing. Recorded in division #n of magnetic tape 40. That is, while the tape drive unit 4 is accessing the division #n on the magnetic tape 40 (including the operation of the changer unit 5), data is stored in the area Bu.
Further, as shown in the path K3, the BOF data corresponding to the head portion of the file in the area Bu is stored in the BOF data area E4.
[0085]
The reproduction of the file recorded on the magnetic tape 40 in this way is performed along the route shown in the schematic diagram of FIG.
When it is determined that a required command (Open File) is supplied from the computer apparatus 41 and a file reproduction request is made, the data storage apparatus 1 first records in the BOF data area E4 as indicated by the path K4. The read BOF data is read and transferred to the computer apparatus 41. At the same time, as shown in the path K5, the data recorded on the magnetic tape 40 is read and stored in the required area Bu of the buffer area E1. That is, while the BOF data recorded in the BOF data area E4 is read and transferred to the computer device 41, the division #n where the file is recorded on the magnetic tape 40 is accessed to read the data. Will be able to. When the transfer of the BOF data recorded in the BOF data area E4 is completed, the data read from the magnetic tape 40 and stored in the buffer area E1 is read out and transferred to the computer device 41. .
[0086]
Thus, by forming and recording the BOF data, the magnetic tape 40 can be accessed while the BOF data is read and transferred to the computer device 41. Real-time performance can be maintained.
[0087]
The capacity of the BOF data recorded in the BOF data area E4 shown in FIGS. 27 and 28 is, for example, the real-time speed of the data transferred from the computer device 41 being V [Mbps], for example, at the reproduction time of T [sec]. Assuming that the corresponding data size is secured,
VT / 8 [MB]
Can be shown as Therefore, when recording data transferred from the computer device 41 at, for example, 6 MMbps with a playback time of 1 minute,
6 × 1 × 60/8 = 45 [MB]
It becomes.
[0088]
If the transfer speed of the data transferred by the computer apparatus 41 is not constant, the computer apparatus 41 notifies the data storage apparatus 1 of the real-time speed by using the “Send Realtime Speed” command before starting the data transfer. To do. In the data storage device 1, data recording is performed in consideration of fragmentation and the like so that continuous reproduction can be guaranteed at the reproduction rate notified by Send Real Time Speed.
[0089]
3-2. Preservation level
In the data storage device 1, the hard disk unit 3 includes a buffer area E 1 and a BOF data area E 4, and data is recorded on the magnetic tape 40. Therefore, the file recorded in the data storage device 1 may have a different recording form for each file. In the present embodiment, this is defined as a file storage level as shown in FIG. 29, for example.
Examples of factors that determine the storage level include:
(1). Whether all or part of the file is recorded in the buffer area E1.
(2). Whether the BOF data of the file is recorded in the BOF data area E4.
(3). Whether all or part of the file is recorded on the magnetic tape 40.
Etc.
[0090]
Based on these factors, the defined storage levels are:
A file in which data is recorded in the buffer area E1, the BOF data area E4, and the magnetic tape 40 is “save level 7”, and a file in which data is recorded in the buffer area E1 and the BOF data area E4 is “save level 6”. ”, A file in which data is recorded in the BOF data area E4 and the magnetic tape 40 is“ storage level 3 ”, and a file in which data is recorded only in the magnetic tape 40 is“ storage level 1 ”. “Storage level 0” indicates an initial value of the storage level, and indicates that the file does not exist in the data storage device 1.
[0091]
These storage levels are raised and lowered depending on, for example, the remaining capacity of the buffer area E1, the remaining capacity of the BOF data area E4, or the number of past accesses to the file in the file information table E2 and the last access time. It is supposed to be.
Based on this storage level, the file recording control for the buffer area E1 and the magnetic tape 40, the BOF data recording control for the BOF data area E3, or the file recorded in the buffer area E1 and the BOF data area E3. Erase control such as erasure of recorded BOF data is performed, and data relating to frequently used files is selectively recorded in the buffer area E1 and the BOF data area E3.
[0092]
3-3. Save level update
3-3-1. "Storage level 0" to "Storage level 6"
Hereinafter, the update of the storage level will be described.
First, according to the flowchart shown in FIG. 30, processing for updating the file storage level from “0” to “6”, that is, processing for newly recording a file in the data storage device 1 will be described. Note that the flowchart shown in this figure assumes that all of the data transferred from the computer device 41 can be stored in the buffer area E1, and that the file data is not recorded on the magnetic tape 40. .
First, it is determined whether or not a “Create File” command for instructing the start of recording has been supplied from the driver unit 44 of the computer device 41 (S401). If it is determined that a write command has been received, Subsequently, the storage capacity of the BOF data is set based on the real-time speed instructed by the supplied “Send Realtime Speed” command (S402). Then, the file information table E2 is updated with information corresponding to the file to be recorded (S403). The information updated in step S403 includes, for example, the last access time as the current time, the storage level as the initial value from “0” to “6”, the access count increment, and the real-time speed as indicated by the “Send Realtime Speed” command. And
[0093]
After updating the file information table E2 as described above, accumulation of data transferred from the computer device 41 to the buffer area E1 is started (S404). Further, when data accumulation is started in the buffer area E1, it is determined whether or not a sufficient amount of data as BOF data has been accumulated in the buffer area E1 (S405), and if it is determined that a sufficient amount of data has been accumulated. The data corresponding to the BOF data is read from the buffer area E1 and recorded in the BOF data area E4 (S406).
After the BOF data is recorded in the BOF data area E4, it is determined whether or not the “Close File” command for instructing the end of the recording is supplied from the computer device 41 (S407), and the “Close File” command is determined. If it is determined that it has been supplied, the write end time of the file information table E2 is updated with the current time (S408), and the recording operation is ended.
As described above, in the data storage device 1, for example, when all data of a file can be stored in the buffer area E 1, for example, the file immediately after recording is managed as “save level 6”. .
[0094]
3-3-2. "Storage level 6" to "Storage level 7"
In the flowchart shown in FIG. 30, an example has been described in which all of the data transferred from the computer apparatus 41 can be stored in the buffer area E1, but the remaining of the buffer area E1 with respect to the transfer data capacity. When the recording capacity is small, recording is performed on the magnetic tape 40.
FIG. 31 is a flowchart for explaining the process of updating the file storage level from “6” to “7” in such a case. Note that the flowchart shown in FIG. 31 is a processing step that is performed as needed during the recording operation as shown in FIG. 30, for example. The relationship between the threshold values in the processing steps described below is as follows:
0 <A1 <A2 <the number of all areas Bu in the buffer area E1
And
[0095]
When the data recording operation is started in the data storage device 1, it is determined whether or not the number of unused areas Bu in the buffer area E1 is smaller than, for example, the threshold value “A2” (S501). If it is determined that the number of areas Bu is smaller than the threshold value “A2”, the file (i) having the lowest priority is searched for among the files set to “save level 6” in the file information table E2 ( S502). Here, the file with the lowest priority is the access history of the file having the “save level 6”, and the access count is the lowest. The file with the oldest access time is assumed. In the following description, the file with the lowest priority is a file corresponding to a condition based on such an access history.
When the file (i) is searched in step S502, the data of the file (i) recorded in the area Bu of the buffer area E1 is recorded in the required division of the magnetic tape 40 (S503). Then, the storage level of the file (i) is updated from “6” to “7” in the file information table E2 (S504).
[0096]
If it is determined in step S501 that the number of areas Bu is larger than the threshold value “A2”, the current time-write end time, that is, the recording is completed in the file set to “save level 6”. It is determined whether or not the elapsed time from the current to the present is greater than a predetermined threshold value T (S505). If it is determined that the elapsed time is greater than the threshold value T, the file (i) having the oldest write end time is set as the file (i) (S506), and the process proceeds to step S503. When the elapsed time is smaller than the threshold value T, the storage level is not updated.
[0097]
3-3-3. "Storage level 7" to "Storage level 3"
FIG. 32 is a flowchart for explaining the process of updating the file storage level from “7” to “3”. The processing steps shown in this figure are performed immediately before using a new division of the magnetic tape 40 when, for example, recording and reproduction are performed.
When the data recording operation is started in the data storage device 1, it is determined whether or not the number of unused areas Bu in the buffer area E1 is smaller than, for example, the threshold value “A1” (S601). When it is determined that the number of areas Bu is smaller than the threshold value “A1”, the file (i) having the lowest priority is searched for among the files set to “save level 7” in the file information table E2 ( S602). However, also in the flowchart shown in this figure, the file with the lowest priority is the one with the smallest number of accesses among the files set to “save level 7”, and more than one file corresponds to this condition. In this case, the file with the oldest last access time is set.
[0098]
When the file (i) is searched in step S602, the data of the file (i) recorded in the area Bu of the buffer area E1 is deleted (S603). Then, the storage level of the file (i) is updated from “7” to “3” in the file information table E2 (S604).
[0099]
3-3-4. "Storage level 3" to "Storage level 1"
FIG. 33 is a flowchart for explaining the process of updating the file storage level from “3” to “1”. The processing steps shown in this figure are performed immediately before writing BOF data in the BOF data area E4, for example.
When the data recording operation is started in the data storage device 1, it is determined whether or not the free capacity of the BOF data area E4 is larger than a predetermined threshold value B (S701). If it is determined that the free area is smaller than the threshold value B, the file (i) having the lowest priority is searched for among the files having the “storage level 3” in the file information table E2 (S702).
When the file (i) is searched in step S702, the BOF data of the file (i) recorded in the area Bu of the buffer area E1 is deleted from the BOF data area E4 (S703). Then, the storage level of the file (i) is updated from “3” to “1” in the file information table E2 (S704). If the free space in the BOF data area E4 is larger than the threshold value B in step S701, it is assumed that the BOF data can be recorded as it is, and the already recorded BOF data is deleted or the storage level is set. Processing such as updating is not performed.
As described above, when the remaining capacity of the BOF data area E4 becomes small, the BOF data of the file with the lowest priority can be deleted, and new BOF data can be recorded.
[0100]
3-3-5. During playback
In the following, the processing steps for updating the storage level based on the number of accesses during data reproduction will be described with reference to FIG.
It is determined whether or not an “OpenFile” command for instructing the start of recording is supplied from the drive unit 44 of the computer device 41 (S801). If it is determined that the “Open File” command is received, the file corresponding to the file to be played back The file information table E2 thus updated is updated (S802). In step S802, for example, the last access time is updated with the current time, and the number of accesses is incremented. Subsequently, the storage level of the file (i) to be reproduced is determined (S803), and if it is determined that the storage level is “1” or “3”, the file information table E2 corresponding to the file (i). Is updated to "7" (S804).
Then, it is determined whether or not all data of the file (i) is stored in the buffer area E1 (S805). If it is determined that all data is stored in the buffer area E1, the data from the magnetic tape 40 is read. Data reading is started and stored in the buffer area E1 (S806). Further, it is determined whether or not the BOF data corresponding to the file (i) is recorded (S807). If it is determined that the BOF data is recorded, reading of the BOF data is started (S808). After the start of reading the BOF data, it is determined whether or not the reading of the BOF data is completed (S809).
If it is determined in step S809 that the BOF data has been read, it is determined whether or not the file (i) has been read (S810). If it is determined that the file has been read, the playback operation is performed. Is finished (S811).
[0101]
If it is determined in step S810 that the reading of the file has not been completed, it is determined whether or not the data read from the magnetic tape 40 is stored in the buffer area E1 (S812). If it is determined that the data to be read is stored in the buffer area E1, the data stored in the buffer area E1 is read (S813) and transferred to the computer device 41. If it is determined in step S807 that there is no BOF data corresponding to the file (i), the BOF data of the file (i) is recorded in the BOF data area E4 (S814). As described above, the capacity of the BOF data area recorded in step S814 is, for example, VT / 8 [MB]. Then, the process returns to step S810 to determine whether or not the reading of the file is completed.
If it is determined in step S805 that all data of the file (i) is stored in the buffer area E1, the process proceeds to step S813, and the data stored in the buffer area E1 is skipped by skipping the BOF data reading step. Is read out.
[0102]
As described above, when a file is reproduced, the number of accesses to the file information table E2 is updated each time the file is accessed, and the BOF data is recorded as necessary. The ranking can be increased, and the high-speed accessibility of the hard disk unit 3 can be useful, and data can be read out.
[0103]
3-3-6. Deleting files
FIG. 35 is a flowchart for explaining an example of processing steps in the case of deleting a file recorded in the data storage device 1.
If it is determined in step S901 that an erasure command has been supplied from the driver unit 44 of the computer apparatus 41, the storage level of the file (i) designated by the erasure command is searched in the file information table E2 (S902). Then, the storage level is determined (S903). If it is determined that the storage level is "7", the data of the file (i) is erased from the magnetic tape 40, the buffer area E1, and the BOF data area E4 (S904). . If it is determined that the storage level is “6”, the data of the file (i) is deleted from the buffer area E1 and the BOF data area E4 (S905). If it is determined that the storage level is “3”, the data of the file (i) is erased from the magnetic tape 40 and the BOF data area E4 (S906). Further, when it is determined that the storage level is “1”, the data of the file (i) is erased from the magnetic tape 40 (S907).
Then, in the file information table E2, the last access time, the write end time, the storage level, the number of accesses, and the real time speed corresponding to the file (i) are initialized (S908).
[0104]
3-4. File life cycle
Next, the life cycle of a file based on the storage level updated as described above will be described with reference to FIG.
As described above, “storage level 0” is set to an initial state, and when a file (i) is newly created and recorded, the storage level is updated to “6”. In a state where the storage level is “6”, data is stored only in the buffer area E1. When the file (i) in this state is reproduced, the access count is incremented and the storage level is not updated.
The condition for updating the storage level from “6” to “7” is that the free space in the buffer area E1 is equal to or less than the threshold value A2, and this update is performed by, for example, recording and reproducing the file (i). This is done when using a new division, if doing so. Similarly to the case where the storage level is “6”, the access count is incremented and the storage level is not updated.
[0105]
The condition for updating the storage level from “7” to “3” is that the free space in the buffer area E1 is less than or equal to the threshold value A1, and a new division is recorded when recording or playback is being performed. Performed when using. If playback is performed after the storage level of the file (i) is updated to “3”, the read data is stored in the buffer area E1, so the storage level is updated to “7” again. Is done.
[0106]
Further, the condition for updating the storage level from “3” to “1” is that the free area of the BOF data area E4 is equal to or less than the threshold value B. When reproduction is performed after the storage level of the file (i) is updated to “1”, the read data is stored in the buffer area E1 as in the case where the storage level is “3”. Therefore, the storage level is updated to “7” again.
[0107]
Further, when the storage level of the file (i) is “6”, “7”, “3”, “1”, and the file (i) is deleted by an instruction from the computer device 41, the storage level is changed. The initial value is set to “0”, and the information stored in the file information table E2 is initialized as described with reference to FIG.
[0108]
Thus, since the data recorded on the hard disk unit 4 or the magnetic tape 40 is managed based on the storage level, the capacity of the hard disk unit 4 can be used efficiently. Therefore, in the data storage device 1, the hard disk unit 4 can be configured with the minimum necessary capacity, so that the cost can be reduced.
Further, since the storage level is raised or lowered based on the access history such as the number of accesses to the file, BOF data is formed and stored in the BOF data area E4 for a file that is accessed relatively frequently. Will be able to. As a result, the frequently accessed file can be read from the hard disk unit 4 and transferred to the computer device 41 for the top portion. That is, even when a reproduction request is received from the computer device 41, it is possible to respond quickly and start data transfer.
Furthermore, for example, for a file that has just been recorded or has recently been played back, the data of the entire file is stored in the buffer area E1 depending on its capacity. Data can be transferred to the computer device 41 without having to access the tape 40.
[0109]
4). Loading / unloading magnetic tape
Next, in order to improve the accessibility to the file recorded on the magnetic tape 40, a case will be described in which an area for performing a load / unload operation is selected based on the recording state of the magnetic tape.
4-1. Load / unload after EOD area
FIGS. 37A and 37B are schematic diagrams for explaining a recording state of a file on one magnetic tape 40 (for example, magnetic tape 40a). In this figure, device area # 1 corresponds to the device area shown in FIG. In this figure, the recordable area of the magnetic tape 40a is shown in units of files, not in units of divisions. Further, the predetermined position of the recordable area from the PBOT to the PEOT on the magnetic tape 40 is, for example, the central part of the recordable area, and this central part corresponds to, for example, the head part of the division # 200. Further, although the magnetic tape 40a is taken as an example, the same applies to the magnetic tape 40b to the magnetic tape 40t.
[0110]
As shown in FIG. 37A, when file # 1 and file # 2 are recorded on the magnetic tape 40a, the current magnetic tape 40a is currently recorded after the last recorded file # 2. In this recording area, an EOD (End of Data) area indicating the end position of the area where data is recorded is formed. For example, in the state where no file is recorded in all recordable areas of the magnetic tape 40a, the device area # 1 is an area where the load / unload operation is performed. That is, when loading is performed at the head portion of the magnetic tape 40a and recording is performed, file # 1 and file # 2 are recorded from the head portion of the magnetic tape 40a. For example, when the recording of the file # 2 is completed, an EOD area is formed.
[0111]
In this manner, when the recording of the file # 1 and the file # 2 is performed, if the end portion of the recorded area has not reached the central part of the recordable area, the area after the EOD area is loaded / Used as an unload area LUA. Therefore, in the state shown in FIG. 37A, for example, when an instruction to eject, for example, tape cassette #A is received from the controller unit 2 of the data storage apparatus 1, the tape drive unit 4 loads / unloads. Moving to the area LUA, an unload operation is executed, and the tape cassette #A is ejected. That is, when the tape cassette #A is loaded into the tape drive unit 4 next time, the magnetic tape 40a is loaded in the load / unload area LUA.
[0112]
As shown in FIG. 37 (b), when file # 3 and file # 4 are recorded following file # 2, the recorded area is recorded when file # 4 is being recorded. You will reach the center of the possible area. In such a case, a device area # 2 is created in order to efficiently load / unload files recorded in an unrecorded area up to PEOT. Thereafter, this device area # is used in the magnetic tape 40a. In step 2, load / unload is performed. The process for creating device area # 2 will be described later.
When the device area # 2 is formed in this way, even when the file # 5 and the file # 6 are recorded, for example, the load / unload is performed by the device area # 2 formed at a position closer to the device area # 1. By performing the operation, the average access time for each file can be shortened and an efficient access operation can be realized.
[0113]
When both the device area # 1 and the device area # 2 are formed on the magnetic tape 40a, the identification method includes area ID detection. By reading the information recorded in the area ID when the magnetic tape 40a is loaded, it is possible to determine whether it is loaded in either device area # 1 or device area # 2, so there has been a request for unloading In this case, it is only necessary to move to any device area corresponding to the detected area ID and shift to the unload operation. Further, even when loaded in the load / unload area LUA, the position on the magnetic tape 40a can be grasped based on the area ID.
Further, when the device area # 2 is formed during the recording of the file after being loaded in the device area # 1, the tape drive unit 4 knows that the creation operation of the device area # 2 has been executed. When there is an unload request after the recording is completed, it is possible to move to the device area # 2 and execute the unload operation.
[0114]
An example of loading / unloading using device area # 2 and load / unload area LUA will be described with reference to FIGS. 38 (a), (b) and FIGS. 39 (a), (b).
FIG. 38A corresponds to, for example, the recording state of the magnetic tape 40a shown in FIG. 37B, and shows a state in which the load / unload operation is performed by the device area # 2. FIG. 38B shows a recording state in which, for example, only the file # 34 is recorded as the data transferred from the computer device 41 as the magnetic tape 40r accommodated in the tape cassette #R.
[0115]
For example, the tape drive unit 4 reproduces the file # 1 of the magnetic tape 40a, and reproduces the file # 34 from the computer device 41 while the rotating drum 24 corresponds to the area where the file # 1 is currently recorded. It is assumed that a command to be supplied is supplied. In this case, after the tape drive unit 4 moves from the file # 1 of the magnetic tape 40a to the device area # 2, the tape drive unit 4 shifts to an unload operation and discharges the tape cassette #A. Then, the tape cassette #R conveyed by the changer unit 5 is loaded.
Here, when the magnetic tape 40r is in a recording state as shown in FIG. 38B, for example, since it was unloaded in the previous load / unload area LUA, the tape cassette # is stored in the tape drive unit 4. When R is loaded, the load / unload area LUA corresponds to the rotary head 24. Therefore, the tape drive unit 4 performs a loading operation on the load / unload area LUA. When the loading operation is completed, the file 34 is moved to the recording position where it is recorded.
[0116]
Also, as shown in FIG. 39B, when the device area # 2 is formed on the magnetic tape 40r, the movement from the file # 6 to the file # 38 is as follows.
In this case, as shown in FIG. 39A, the tape drive unit 4 moves from the file # 6 of the magnetic tape 40a to the device area # 2, and then shifts to the unload operation to eject the tape cassette #A. Then, the tape cassette #R conveyed by the changer unit 5 is loaded. Here, when the magnetic tape 40r is in a recording state as shown in FIG. 39B, for example, since it was unloaded in the previous device area # 2, the device area when the tape cassette #R is loaded. # 2 corresponds to the rotary head 24. Therefore, the tape drive unit 4 performs a loading operation on the load / unload area LUA. When the loading operation is completed, the file # 38 is moved to the recording position.
[0117]
4-2. Load / unload in device area # 1
When the end of the recordable area of one magnetic tape 40a does not reach the center, it is not always necessary to load / unload in the load / unload area LUA after the EOD area.
For example, as shown in FIG. 40 (a), when file # 1 and file # 2 are recorded and the end of the recordable area does not reach the center, loading / unloading is performed. It is also possible to use device area # 1. In this case, the device area # 1 corresponds to the rotary head 24 when the tape cassette #A is loaded in the tape drive unit 4. When a file is played back and an unload request is made in a state where the device area # 2 is not formed, the process returns to the device area # 1 and shifts to an unload operation.
Then, by recording file # 3 and file # 4, when the end of the recordable area reaches the center, a device area # 2 is created as shown in FIG. Thereafter, the load / unload operation is performed in the device area # 2.
[0118]
The transition from the magnetic tape 40a in which the device area # 2 is formed to the magnetic tape 40r in which the device area # 2 is not formed will be described with reference to FIGS.
In the tape drive unit 4, for example, when the current position of the magnetic tape 40a is the file # 1, for example, when the computer device 41 receives a request to reproduce the file # 34 of the magnetic tape 40r, the tape drive unit 4 reads the magnetic tape 40a. The device moves to the device area # 2, shifts to an unload operation, and discharges the tape cassette #A. When the tape cassette #R is loaded by the changer unit 5, the magnetic tape 40r is loaded in the device area # 1 and moved to the position where the file # 35 is recorded.
[0119]
4-3. Load / unload process
FIG. 42 is a flowchart illustrating an example of processing steps in the control unit 11 of the data storage device 1 when loading / unloading is performed in the load / unload area LUA that is located after the EOD area. In addition, the magnetic tape 40 shown below has shown any one magnetic tape in the magnetic tapes 40a-40t.
For example, it is determined whether or not a reproduction request for a file has been received from the computer device 41 (S1001). If it is determined that an access request has been received, the recording position of the file to be accessed is searched with reference to the file information table E2 or the like. (S1002). When a tape cassette is currently loaded in the tape drive unit 4, it is determined whether or not the tape cassette needs to be replaced when reproducing a desired file (S1003). If it is determined, it is determined whether or not device area # 2 has been created on the currently loaded magnetic tape 40 (S1004). This determination is made based on information such as the area ID read when the magnetic tape 40 is loaded. When the magnetic tape 40 is loaded in the device area # 2, it is assumed that the device area # 2 has been created.
[0120]
If it is determined that the device area # 2 has been created, the device moves to the device area # 2 and unloads the magnetic tape 40 (S1005). If it is determined in step S1004 that the device area # 2 has not been created, the device moves to the load / unload area LUA and unloads (S1006).
When the magnetic tape 40 is unloaded, the tape drive unit 4 ejects the tape cassette, loads the tape cassette conveyed by the changer unit 5 (S1007), and loads the magnetic tape 40 of the loaded tape cassette (S1008). ). In this case, in step S1007, the magnetic tape 40 is loaded in the previously unloaded area. At this time, for example, the area ID recorded on the magnetic tape 40 is detected, and the loaded area is identified (S1009). That is, the magnetic tape 40 loaded in step S1009 can be unloaded in the area corresponding to the area ID detected in step S1009. Then, it moves to the recording position of the file corresponding to the access request and starts reading data (S1010).
[0121]
If it is determined in step S1003 that it is not necessary to replace the tape cassette, the process advances to step S1010 to move to the file recording position corresponding to the access request in the same magnetic tape 40 and start reading data.
For example, as described with reference to FIG. 41, when the unload operation is performed in the device area # 1 until the device area # 2 is created, the device area # 1 is moved in step S1006 shown in FIG. You can do it.
[0122]
4-4. Connecting data
In the magnetic tape 40 (at), the device area # 2 is created at the beginning of the division # 200 where, for example, the end of the recordable area is the central portion, so the device area # 2 stores the file data. It may be recorded in an interrupted manner. In this case, when creating the device area # 2, for example, the recording of the file data transferred from the computer device 41 is temporarily interrupted. Therefore, the required connection data is recorded in the connection data area E5 of the hard disk unit 4 while the device area # 2 is being created.
[0123]
FIG. 43 is a schematic diagram for explaining a data flow in the case of creating device area # 2 when recording from the computer apparatus 41 is performed.
When the data of the file # 4 is transferred from the computer device 41 as indicated by the path K11, it is first stored in the buffer area E1. When the data in units of division is stored in the buffer area E1, the data is sequentially read from the buffer area E1 and recorded on the magnetic tape 40 (any one of the magnetic tapes 40a to 40t).
Here, if it is determined that the recording position on the magnetic tape 40 has reached the beginning of the division # 200, the tape drive unit 4 creates the device area # 2. At this time, the recording of the file # 4 on the magnetic tape 40 is interrupted, but the buffering is continued in the buffer area E1, and after the creation of the device area # 2 is completed, as shown in the path K12. Subsequently, the data of the file # 4 is recorded on the magnetic tape 40.
[0124]
That is, the transfer transition of data (D1, D2, D3) from the buffer area E1 to the magnetic tape 40 and the recording operation to the magnetic tape 40 will be described. The data D1 is transferred from the buffer area E1 to the tape drive unit 4. When recording on the magnetic tape 40 and creating the device area # 2, data transfer from the buffer area E1 to the tape drive unit 4 is temporarily stopped, and only buffering of data transferred from the computer device 41 is performed. . When the device area # 2 has been created, the data D2 and D3 stored in the buffer area E1 during that time are transferred to the tape drive unit 4 and recorded on the magnetic tape 40.
[0125]
In this way, all the data of the file # 4 can be recorded on the magnetic tape 40, but the data D1, D2, D3 that are supposed to be continuous are divided by the device area # 2. Therefore, when the file # 4 is reproduced, all the data of the file # 4 is read from the magnetic tape 40, and when the data stored in the buffer area E1 is transferred to the computer device 41, the device area # 2 is scanned on the magnetic tape 40. During this period, reading of data from the magnetic tape 40 is interrupted, making it difficult to maintain real-time performance. Therefore, at the time of recording, the data D2 corresponding to the period during which the device area # 2 is created is read from the buffer area E1 and recorded as connection data in the connection data area E5. As a result, when file # 4 is reproduced, it is as shown in the schematic diagram of FIG.
[0126]
When reading of data from the magnetic tape 40 is started, the read data is stored in the buffer area E1. For example, when the data D1 is read from the magnetic tape, the buffer area E1 is sequentially stored as indicated by a path K14. Then, as shown in the path K15, the data stored in the buffer area E1 is transferred to the computer device 41. However, during the period of scanning the device area # 2 on the magnetic tape 40, the connection data (D2) stored in the connection data area E5 is read and transferred to the computer apparatus 41 as shown by the path K16. Then, after passing through the device area # 2, the reading of the data D2 is started, and the data D3 stored in the buffer area E1 is read as indicated by the path K17 from the time when the data D2 is stored in the buffer area E1. Transfer to computer device 41.
As a result, even when a file recorded across the device area # 2 is read from the magnetic tape, the data transferred to the computer device 41 can be prevented from being interrupted, so that the real-time property of the reproduction data is maintained. Will be able to.
[0127]
FIG. 45 is a flowchart for explaining an example of processing steps in the case of recording a file while recording connection data in the data storage device 1. Note that the flowchart shown in this figure shows an example in which recording is performed on the magnetic tape 40 currently loaded in the tape drive unit 4.
After a required tape cassette is loaded in the tape drive unit 4, when a magnetic tape is loaded and a recording operation is started (S1101), buffering is started with respect to the buffer area E1 (S1102) and stored in the buffer area E1. The recorded data is recorded on the magnetic tape 40 in units of divisions (S1103). When recording is started on the magnetic tape 40, processing steps are selected based on whether or not device area # 2 has been created thereafter (S1104). For example, if the device area # 2 has not been created, the process advances to step S1105 to determine whether or not the recording position of the magnetic tape 40 has reached the center portion. If it is determined that the center portion has been reached, device area # 2 is created on the magnetic tape 40 (S1106). Then, it is determined whether or not the transfer of the file from the computer device 41 is completed (S1107). Here, if it is determined that the file transfer is not completed, the same file is recorded across the device area # 2, so the connection data is recorded in the connection data area E5 (S1108). Then, the process returns to step S1103 to continue recording data.
If it is determined in step S1107 that the file transfer has ended, it is assumed that the same file is not recorded across the device area # 2, and the recording operation is terminated without recording the connection data (S1109). .
[0128]
If it is determined in step S1104 that, for example, device area # 2 has been created, it is determined whether or not the transfer of the file from the computer apparatus 41 has ended (S1110). If the transfer of the file has not ended Returns to step S1103 to continue the recording operation. If it is determined that the file transfer has been completed, the process advances to step S1109 to end the recording operation.
[0129]
FIG. 46 is a flowchart for explaining an example of processing steps when the data storage device 1 reproduces a file in which connection data is recorded.
After the required tape cassette is loaded in the tape drive unit 4, when the magnetic tape 40 is loaded and the reproducing operation is started (S1201), the data read from the magnetic tape 40 is stored in the buffer area E1 (S1202). Further, it is determined whether or not the data read from the magnetic tape 40 is sufficiently stored in the buffer area E1 (S1203). If it is determined that sufficient data is stored, the data stored in the buffer area E1 is stored in the computer. The data is transferred to the device 41 (S1204).
[0130]
If it is determined in step S1203 that the data read from the magnetic tape 40 is not sufficiently stored in the buffer area E1, the process proceeds to step S1207, and the buffering to the buffer area E1 recorded on the magnetic tape 40 is performed. Continue to go. Then, it is determined whether or not device area # 2 has been detected (S1208). If it is determined that device area # 2 has been detected, device area # 2 is fast-forwarded (S1209) to create a connection data area E5. The connection data corresponding to the file currently being reproduced is read out and transferred to the computer device 41 (S1210).
If it is determined in step S1208 that the device area # 2 has not been detected, the data stored in the buffer area E1 in step S1208 is transferred to the computer device 41 (S1211).
[0131]
Then, when data transfer to the computer apparatus 41 is started in steps S1204, S1210, and S1211, it is determined whether or not data reading from the magnetic tape 40 is completed (S1205), and the file reading is completed. If it is determined that the data is stored in the buffer area E1, the reproduction operation is terminated when the data stored in the buffer area E1 is transferred to the computer device 41 (S1206). If it is determined in step S1205 that the file has not been read, the process returns to step S1203 to continue the reproduction operation.
[0132]
Thus, until the end of the recorded area on the magnetic tape 40 reaches the central portion of the recordable area, for example, loading / unloading is performed by either the device area # 1 or the load / unload area LUA, In addition, when the central portion of the recordable area is reached, a device area # 2 is created, and thereafter, loading / unloading is performed by the device area # 2, so that based on the usage status of the magnetic tape 40, Efficient loading / unloading can be performed. As a result, the average access time for the file recorded on the magnetic tape 40 can be shortened, and the operation from the reception of the access request to the start of data reading can be performed quickly. Become.
[0133]
In addition, by forming the device area # 2, the connection data is recorded on the hard disk unit 4 in consideration of the fact that the recorded file is divided by the device area # 2 and the accessibility to the recorded data is deteriorated. I try to keep it. Thus, when data reading is interrupted by scanning the device area # 2, the connection data can be read and transferred to the computer apparatus 41. Therefore, it is possible to realize data reproduction that maintains real-time characteristics.
[0134]
In the present embodiment, the predetermined position of the recordable area in which the device area # 2 is created has been described by taking the central portion of the magnetic tape 40 as an example, but the device area # 2 is not necessarily in the magnetic tape 40. It is not necessary to form it in the central portion, and it may be formed in a position where, for example, a load / unload operation can be performed efficiently.
[0135]
5). BOF data optimization
Since the access time differs depending on the distance from the loading position of the magnetic tape 40 to the file recording position, the access time for each file is different. Therefore, when forming BOF data corresponding to each file, it is only necessary that relatively small-capacity BOF data be formed for the files arranged near the load position.
Therefore, first, an example of optimizing BOF data in one magnetic tape (for example, magnetic tape 40) will be described.
[0136]
First, an example of setting the volume of BOF data based on the distance from the device areas # 1 and # 2 will be described with reference to the schematic diagrams of FIGS. In the following description, an example in which the device area # 2 is created in the central portion of the magnetic tape 40 is given as an example.
FIG. 47A shows a state where only the device area # 1 is formed on the magnetic tape 40a, for example, and the file # 1, file # 2, and file # 3 are recorded following the device area # 1. Indicates the state. In this case, when the tape cassette #A in which the magnetic tape 40a is stored in the tape drive unit 4 is loaded, the loading operation is performed in the device area # 1 as described above, and each file is changed according to a required reproduction command. (# 1 to # 3) will be accessed.
In this case, as shown in FIG. 47B, when BOF data corresponding to each file (# 1 to # 3) is formed in the BOF data area E3, the capacity is fixed size A. That is, the BOF data is formed with the same size until the end of the recorded area reaches, for example, the central portion of the recordable area and the device area # 2 is formed.
[0137]
Then, after the device area # 2 is formed as shown in FIG. 48A, a file is transferred from the position where the device area # 2 is formed as shown in FIG. The volume of BOF data is changed according to the recorded position.
At the time when device area # 2 is created, BOF data of fixed size A corresponding to each file (# 1 to # 3) is formed as shown in FIG. 47 (b). In this case, a part of the BOF data can be deleted according to the distance from the device area # 2.
In the example shown in FIG. 48B, it is assumed that there is a relatively long distance from the device area # 2 to the file # 1, and the BOF data # 1 corresponding to the file # 1 remains the fixed size A. The BOF data # 2 corresponding to the file # 2 recorded at a position closer to the file # 1 has a size B smaller than the fixed size A because the file # 2 can be accessed in a shorter time than the file # 1. In addition, the BOF data # 3 corresponding to the file # 3 recorded at a position closer to the file # 2 can be accessed in a shorter time than the file # 2, so that the size C is smaller than the fixed size B. To.
Therefore, the capacity of each BOF data (# 1, # 2, # 3) is
BOF data # 1> BOF data # 2> BOF data # 3
It becomes.
[0138]
In addition, regarding the BOF data corresponding to the files recorded after the device area # 2, the size is set in advance based on the distance from the device area # 2. Thus, for example, the BOF data # 4 corresponding to the file # 4 recorded at a position close to the device area # 2 is BOF data # 4 corresponding to the file # 5 recorded at a position farther than the size D and the file # 4. 5 can be formed to be size E, and BOF data # 6 corresponding to file # 6 recorded at a position farther than file # 5 can be formed to size F.
Therefore, the capacity of each BOF data (# 4, # 5, # 6) is
BOF data # 4 <BOF data # 5 <BOF data # 6
It becomes.
[0139]
As a factor for determining the capacity of the BOF data, for example, the time required for the operation shown in FIG.
For example, the time required for ejecting the tape cassette from the tape drive unit 4 and storing the changer unit 5 in a predetermined position, and the time required for removing the desired tape cassette from the changer unit 5 and loading the tape drive unit 4 are as follows. It is almost constant for each cassette. Further, after loading the magnetic tape 40 in the tape drive unit 4, the time from the start of data reading to the preparation of a required amount of data to be transferred to the computer device 41 is substantially constant. .
However, for example, the time required for the unloading operation of the magnetic tape 40 in the tape drive unit 4 depends on the distance between the current position and the device area # 2 (unload area), and a desired file is loaded by loading the magnetic tape 40. The time required for the movement to the recording position also depends on the distance between the desired file position and device area # 2 (load area).
[0140]
Taking this into consideration, the BOF data capacity is s (n) [MB], the distance from the device area # 2 is d (n) [m], the coefficient for determining the data capacity is α, and the data capacity is determined. When the fixed part is β, the BOF data capacity s [MB] corresponding to the distance from the device area # 2 is
s [MB] = β [MB] + α [MB / m] × d [m] (1)
It can be.
[0141]
It should be noted that the time t [s] required for cueing is a constant value tx for the transport time of the changer unit 5 and tk for determining the time.
t [s] = constant value tx [sec] + coefficient tk [s / m] × d [m]
It can be.
[0142]
FIG. 50 is a flowchart showing an example of processing steps for optimizing the recorded BOF data capacity and setting the optimum BOF data capacity.
The flowchart shown in this figure is a process executed when recording BOF data based on a required condition as described in “3. Data Storage Level”.
If BOF data is to be formed, it is first determined whether or not device area # 2 is formed (S1301). If it is determined that device area # 2 is not formed, the capacity of BOF data is determined. Is set to a fixed value A (S1302), and BOF data is recorded in the BOF data area E4 (S1303). Then, it is determined whether or not the device area # 2 has been created along with the recording of the file (S1304). If it is determined that the device area # 2 has been created, the current recording is performed based on the above equation 1. The optimum capacity of BOF data of all existing files is obtained, and the data corresponding to the difference from the capacity obtained by the above equation 1 in the already recorded BOF data is deleted (S1305). By such processing steps (S1301 to S1305), the BOF data # 1, # 2, and # 3 shown in FIG. 48B are formed.
[0143]
If it is determined in step S1301 that the device area # 2 has already been created, the capacity of the BOF data is set by applying the above equation (1) based on the file recording position (S1306). Thereby, the capacities of the BOF data # 4, # 5, and # 6 shown in FIG. 48B are set. Then, the BOF data is recorded in the BOF data area E4 with the capacity set in step S1306 (S1307).
[0144]
Thus, by optimizing the capacity of the BOF data based on the positional relationship between the device area # 2 and the recorded file, the recording capacity in the BOF data area E3 can be minimized. The recording area of the hard disk unit 3 can be used efficiently.
Further, after the device area # 2 is created, the capacity is obtained each time the BOF data is recorded. Therefore, compared to the case where BOF data is recorded at a fixed size before creating device area # 2, BOF data can be recorded by a recording operation in a short time.
[0145]
In the present embodiment, the example of setting the capacity of BOF data on the basis of the device area # 2 has been described. However, when the device area # 2 is not created, the device area # 1 is used as a reference. Thus, the BOF data capacity may be set based on the distance from the device area # 1 to the file.
[0146]
By the way, in the data storage device 1, a plurality of tape cassettes including the changer unit 5 can be used. Accordingly, it is possible to optimize BOF data for each magnetic tape stored in each tape cassette.
For example, in FIG. 51, the recording state of the magnetic tape 40a is file # 1 to file # 6, the recording state of the magnetic tape 40b is file # 7 to file # 12, and the recording state of the magnetic tape 40c is file # 13 to file # 18. An example is given. For convenience of explanation, when BOF data is formed for all of these files and the BOF data is optimized in one magnetic tape 40 as described above, the BOF corresponding to each file (# 1 to # 18). Data (# 1 to # 18) is recorded in the BOF data area E3 as shown in FIG.
[0147]
However, a required time is also required when the tape cassette is ejected / loaded by the changer unit 5.
FIG. 53 is a diagram schematically showing the arrangement of the tape drive unit 4 and the changer unit 5. In the changer unit 5, the tape cassettes #A to #T are stored in predetermined positions. Therefore, when the transport speed of the changer unit 5 is constant, the transport time from the changer unit 5 to the tape drive unit 4 differs for each tape cassette as described with reference to FIG.
That is, the time t1 from when the tape cassette #A is transported from the changer unit 5 to the time when it is loaded into the tape drive unit 4, and similarly, from when the tape cassette #T is transported from the changer unit 5 and loaded into the tape drive unit 4. There is a considerable difference at time t2.
[0148]
Therefore, when a tape cassette #A is currently loaded in the tape drive unit 4, a command requesting reproduction of a file recorded on the magnetic tape 40b of the tape cassette #B is received, and a tape cassette #T. The time required to access a desired file and start reproduction differs from when a command requesting reproduction of a file recorded on the magnetic tape 40t is received.
Therefore, by optimizing the capacity of BOF data according to the distance between the tape cassette storage position and the tape drive unit 4 in the changer unit 5, the magnetic tape 40 from the magnetic tape 40 stored at a position far from the tape drive unit 4 can be used. Even when it takes a relatively long time to start reading data, the BOF data can be transferred to the computer device 41 until the reading is started.
[0149]
FIG. 54 shows, as an example, magnetic tapes 40a, 40b, and 40c stored in tape cassettes #A, #B, and #C as a part of the tape cassettes stored in the changer unit 5, and these magnetic tapes 40a. , 40b, 40c schematically shows the capacity of BOF data # 1 to # 18 corresponding to the files recorded in the files.
The BOF data (# 1 to # 6) of the magnetic tape 40a shown in FIG. 54 (a) is shown as the capacity similar to the example described above with reference to FIG. 52, but in FIG. 54 (b). The BOF data (# 7 to # 12) of the magnetic tape 40b shown has a larger capacity than the BOF data (# 1 to # 6) in consideration of the distance between the tape cassette #B and the tape drive unit 4. Record. Further, the BOF data (# 13 to # 18) of the magnetic tape 40c shown in FIG. 54 (c) is arranged such that the tape cassette #C is located farther from the tape drive # 4 than the tape cassette #B. Correspondingly, recording is performed with a capacity larger than that of the BOF data (# 7 to # 12).
In this case, if the tape cassette transport time is γ, the capacity of the BOF data is
s [MB] = β [MB] + α [MB / m] × d [m] + γ Expression 2
It can be. That is, the volume of BOF data may be obtained by Equation 2 in Step S1305 and Step S1306 of the flowchart described in FIG.
[0150]
Thus, by recording BOF data with a capacity corresponding to different transport times for each tape cassette (#A to #T), even if it takes a long time to transport the tape cassette by the changer unit 5, Data transfer to the computer device 41 can be prevented from being interrupted within that time.
[0151]
【The invention's effect】
As described above, the recording / reproducing apparatus of the present invention has the following effects.
In the recording / reproducing apparatus according to the first aspect, the capacity of the cue data is obtained based on the transport time of the tape cassette by the changer means and the distance between the load / unload area created on the magnetic tape and the file. . Therefore, even if a file to be reproduced is recorded at a position far from the load / unload area on the magnetic tape and further time is required for transporting the tape cassette, cueing data having a capacity corresponding to the time is recorded. be able to. As a result, the tape cassette needs to be replaced during reproduction, and the time required for transporting the tape cassette by the changer means is long, and even when the tape drive means requires time to move to the file recording position, the head corresponding to the file is in the meantime. By reading out the extracted data, the accessibility to the file can be improved and the real-time property can be maintained without interrupting the reproduction data.
In addition, since the transport time by the changer means is short and the file recorded on the magnetic tape at a position close to the load / unload area, it is possible to record relatively small-capacity cue data. The hard disk drive means can be used efficiently. Furthermore, processing related to recording of cue data can be performed in a short time.
[0152]
The recording / reproducing apparatus according to claim 2, after creating the second load / unload area at a predetermined position on the magnetic tape, the second load / unload area and the file recorded on the magnetic tape. The capacity of the cue data is obtained based on the distance of the data, and the data corresponding to the difference from the cue data already recorded is deleted. In other words, for the cue data that corresponds to a file that is recorded near the second load / unload area and has good accessibility after loading, by deleting a part of the cue data, the minimum necessary cue data is obtained. It becomes possible to record. Therefore, the capacity of the hard disk drive means can be used efficiently.
Furthermore, after the second load / unload area is created, the recording / reproducing apparatus according to claim 3 obtains the capacity in advance based on the second load / unload area and the recording position of the file. Since the cue data is recorded in the memory, the capacity of the hard disk drive means can be used efficiently.
[0153]
According to a fourth aspect of the present invention, the capacity of the cue data is set based on the distance between the load / unload area created on the magnetic tape and the file. Therefore, it is possible to record cueing data having a capacity corresponding to the movement time from loading of the magnetic tape to the file recording position, and during the movement to the desired file recording position after loading, the file By reading the cue data corresponding to the file, the accessibility to the file can be improved.
[Brief description of the drawings]
FIG. 1 is an external view showing an entire data storage system according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration example of a computer device and a data storage device.
FIG. 3 is a diagram illustrating a display example of a window displayed on the monitor device.
FIG. 4 is a block diagram illustrating a configuration example of a data storage device.
FIG. 5 is a block diagram illustrating a configuration example of a tape drive unit.
FIG. 6 is a schematic diagram for explaining a data flow when data transferred from a computer device is recorded on a magnetic tape.
FIG. 7 is a diagram illustrating a layout of a magnetic tape.
FIG. 8 is a diagram illustrating a layout of tracks formed on a magnetic tape.
FIG. 9 is an explanatory diagram of an ID area.
FIG. 10 is a diagram for explaining a division of a magnetic tape disposed in a changer section.
FIG. 11 is a diagram for explaining a configuration example of a division.
FIG. 12 is a diagram illustrating an example of a recording area formed in a hard disk unit.
FIG. 13 is a diagram illustrating a buffer area.
FIG. 14 is a diagram illustrating a file information table.
FIG. 15 is a diagram illustrating a division access map.
FIG. 16 is a diagram illustrating file fragmentation on a magnetic tape.
FIG. 17 is a diagram illustrating a driver unit in a computer device.
FIG. 18 is a schematic diagram illustrating cluster addresses.
FIG. 19 is a diagram illustrating a driver unit in a computer device.
FIG. 20 is a diagram illustrating an example of a command output from the driver unit to the data storage device when data is recorded.
FIG. 21 is a diagram illustrating an example of a command output from the driver unit to the data storage device during data reproduction.
FIG. 22 is a diagram illustrating an example of a command output from the driver unit to the data storage device when data is recorded.
FIG. 23 is a flowchart illustrating processing steps on the computer device side when data is recorded.
FIG. 24 is a flowchart illustrating processing steps on the computer device side when data is reproduced.
FIG. 25 is a flowchart illustrating processing steps on the data storage side when data is recorded.
FIG. 26 is a flowchart illustrating processing steps on the data storage side when data is reproduced.
FIG. 27 is a schematic diagram illustrating a data flow when recording is performed in the data storage device.
FIG. 28 is a schematic diagram for explaining a data flow when reproduction is performed in the data storage device.
FIG. 29 is a diagram illustrating a storage level.
FIG. 30 is a flowchart illustrating an example of storage level update (during recording).
FIG. 31 is a flowchart illustrating an example of storage level update (during recording).
FIG. 32 is a flowchart illustrating an example of storage level update (during recording).
FIG. 33 is a flowchart illustrating an example of storage level update (during recording).
FIG. 34 is a flowchart illustrating an example of storage level update (during reproduction).
FIG. 35 is a flowchart illustrating an example of storage level update (during erasure).
FIG. 36 is a diagram for explaining a life cycle of a file.
FIG. 37 is a diagram for explaining a recording state of a magnetic tape and a load / unload area.
FIG. 38 is a diagram for explaining an example in a case where a load / unload operation is performed in a load / unload area.
FIG. 39 is a diagram for explaining an example when a load / unload operation is performed in device area # 2.
FIG. 40 is a diagram for explaining the recording state of the magnetic tape and the EOD area.
FIG. 41 is a diagram for explaining an example in a case where a load / unload operation is performed behind an EOD area.
FIG. 42 is a diagram illustrating an example of processing steps when performing a load / unload operation.
FIG. 43 is a schematic diagram illustrating an example of creating connection data.
FIG. 44 is a schematic diagram illustrating an example in which connection data is used during reproduction.
FIG. 45 is a diagram illustrating a flowchart for explaining an example of processing steps when creating connection data;
FIG. 46 is a diagram illustrating a flowchart for explaining an example of a processing step when connection data is used during reproduction.
FIG. 47 is a schematic diagram for explaining BOF data corresponding to a file recorded on a magnetic tape.
FIG. 48 is a schematic diagram for explaining a case where BOF data is optimized.
FIG. 49 is a diagram showing factors in the case of optimizing BOF data.
FIG. 50 is a diagram illustrating a flowchart for explaining a processing step when recording BOF data.
FIG. 51 is a schematic diagram showing files recorded on a plurality of magnetic tapes.
52 is a diagram for explaining BOF data corresponding to each file shown in FIG. 51;
FIG. 53 is a schematic diagram illustrating the positional relationship between the changer unit and the tape drive unit, and the tape cassette transport time.
FIG. 54 is a schematic diagram for explaining a case where BOF data is optimized based on the transfer time of the changer unit.
[Explanation of symbols]
1 data storage device, 2 controller unit, 3 hard disk unit, 4 tape drive unit, 5 changer unit, 6, 9 I / F unit, 7 buffer controller, 7a, 7b direct memory access, 8 I / F buffer, 11 control unit , 12 ROM, 13 RAM, 14 bus, 20 I / F section, 21 controller section, 21a direct memory access, 21b signal processor, 22 group buffer, 23 RF processing section, 24 rotating drum, 25A, 25B, 25C playback head, 26A, 26B Recording head, 27 Mechanical controller, 28 Servo controller, 29 Control unit, 30 ROM, 31 RAM, 32 EEP-ROM, 35 bus, 40 Magnetic tape, 41 Computer device, 42 Application, 43 Mail system, 44 driver unit, E1 buffer area, E2 file information table, E3 division access map, E4 BOF data area, E5 connecting data area

Claims (3)

Loading the tape cassette magnetic tape recording area of a predetermined unit is formed with a plurality are housed, recorded on a magnetic tape housed in the tape cassette, and row shoot Pudoraibu means playback,
At least a buffer area when data is recorded and reproduced in the tape drive means, and a cue data corresponding to a file recorded on the magnetic tape and recording cue data when the file is reproduced Hard disk drive means having an area;
Cue data recording control means for recording cue data in a fixed capacity in the cue data area;
End of the recorded area in the magnetic tape, when reaching a predetermined position of the recording area, and Carlo over de / unload area creating means to create a B over de / unload area to said predetermined position,
Said load / unload area formed on said magnetic tape, based on the distance of the file recorded on the magnetic tape, and cue data capacity setting means for determining the capacity of the cue data,
When the load / unload area is created at the predetermined position by the load / unload area creation means, the capacity obtained by the cue data capacity setting means from the cue data already recorded A data erasing means for erasing data corresponding to the difference between,
Record reproducing device provided with a. The cue data recording control means for beginning data of the file to be recorded on the magnetic tape after the load / unload area is created by the load / unload area creating means, the cue data capacity setting The recording / reproducing apparatus according to claim 1 , wherein recording is performed with a capacity determined by the means. The magnetic tape has a first load / unload area formed substantially at the top position of the tape, and the load / unload area created by the load / unload area creation means at the predetermined position The recording / reproducing apparatus according to claim 1, wherein the recording / reproducing apparatus is a second load / unload area.

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