JP2001266542A - Magnetic recording/reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required for the access start of a magnetic tape much more than before by applying a magnetic recording/reproducing device to a tape streamer for backing up data of such as a server. SOLUTION: When performing loading, before performing servo locking, information necessary for the access of the magnetic tape is made acquirable by the selective acquisition of data reproduced correctly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus, and can be applied to, for example, a tape streamer for backing up data in a server or the like. The present invention reduces the time required to start accessing the magnetic tape by enabling the information necessary for accessing the magnetic tape to be acquired by selectively acquiring correctly reproduced data before loading the servo lock during loading. So that it can be much shorter than

[0002]

2. Description of the Related Art Conventionally, a tape streamer records, at the beginning of a magnetic tape, file names and positional information necessary for accessing each file recorded on the magnetic tape in a predetermined area of the magnetic tape. The file has been made accessible.

[0003] That is, when a magnetic tape is loaded, the tape streamer accesses the head of the magnetic tape to obtain data necessary for accessing user data, and rapidly feeds the magnetic tape as needed in accordance with the data to start the head. After that, desired data is accessed. When the magnetic tape is ejected, the magnetic tape is rewound, and if necessary, such data is updated and the magnetic tape is unloaded.

On the other hand, for example, Japanese Patent Application Laid-Open No. Hei 8-25538
In the technique disclosed in Japanese Patent Application Laid-Open No. 8 (1996) -1995, a method of unloading a magnetic tape without rewinding to the beginning by recording this type of data at a recording end position of a file has been proposed. In this case,
The next time a magnetic tape is loaded, access to the magnetic tape can be started based on the data necessary for accessing the magnetic tape recorded in the unloaded area, and the access to the magnetic tape can be started much more than before. Can be shortened.

[0005]

If it is possible to further shorten the time required for starting access to such a magnetic tape, it is considered that the usability of this type of magnetic recording / reproducing apparatus can be improved.

The present invention has been made in view of the above points, and is intended to propose a magnetic recording / reproducing apparatus capable of further reducing the time required for starting access to a magnetic tape as compared with the related art. .

[0007]

According to the first aspect of the present invention, in order to solve the above-mentioned problem, data necessary for accessing the magnetic tape is repeatedly transmitted to the nearest recordable portion in response to an instruction to eject the tape cassette. After recording, the magnetic tape is rewound by a predetermined distance within the range of the repetitive recording, and the magnetic tape is drawn into and discharged from the tape cassette. Is started to make the distance equal to the distance until the tracking control system performs servo lock.

According to the fourth aspect of the present invention, after the magnetic tape is pulled out from the tape cassette and placed on the magnetic tape running path, the operations of the magnetic tape running system and the tracking control system are started, and the magnetic tape is correctly reproduced from the magnetic tape. Starting the selective capture of the data and the construction of the data necessary for reproducing the magnetic tape with the captured data, so that at least when the tracking control system completes the servo lock, it is necessary to reproduce the magnetic tape. After completing the acquisition of the necessary data, the magnetic tape is accessed based on the data necessary for reproducing the acquired magnetic tape.

According to the first aspect of the present invention, after the data necessary for accessing the magnetic tape is repeatedly recorded, the magnetic tape is rewound and discharged by a predetermined distance within the range of the repeated recording, Is at least the distance from when the magnetic tape is pulled out of the tape cassette and the running of the magnetic tape is started and the tracking control system is servo-locked. By selectively taking in data, when the magnetic tape starts running without pre-rolling and the magnetic tape running system is servo-locked, the acquisition of data necessary for accessing this magnetic tape can be completed. it can. Therefore, the magnetic tape can be set in the magnetic tape running system and the running of the magnetic tape can be started, so that the magnetic tape can be accessed in a very short time.

According to the fourth aspect of the present invention, after the magnetic tape is pulled out from the tape cassette and placed on the magnetic tape running path, the operations of the magnetic tape running system and the tracking control system are started, and the magnetic tape is reproduced correctly. By starting the selective capture of the data to be read and the construction of the data necessary for reproducing the magnetic tape by the captured data, at least when the tracking control system completes the servo lock, the reproduction of the magnetic tape is started. Once the necessary data has been acquired, access to the magnetic tape can be started at least when the magnetic tape running system is servo-locked, so that access to the magnetic tape can be started in a shorter time than in the past. can do.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(1) Configuration of First Embodiment (1-1) Overall Configuration FIG. 1 is a perspective view showing a backup system according to a first embodiment of the present invention. The backup system 1 is configured by arranging a tape streamer 3 and the like on a large console 2. That is, in this backup system 1, a tape streamer 3, a power supply unit 4, and a CPU unit 5 are arranged in this order from the lower side of the front, and the transport mechanism 6 of the tape cassette is arranged on the back side.

The power supply unit 4 supplies power to each part of the backup system 1 and the CPU unit 5
Controls the operation of the entire backup system 1. The tape streamer 3 records data from a host computer on a tape cassette loaded by the transport mechanism 6, reproduces the data recorded on the tape cassette, and outputs the data to the host computer.

The transport mechanism 6 is configured so that a plurality of tape cassettes can be stored in the shelf 6A. Under the control of the CPU unit 5, the tape cassette held in the shelf 6A is transported and loaded into the tape streamer 3. Conversely, the tape cassette discharged from the tape streamer 3 is transported to the original shelf 6A. For this reason, the transport mechanism 6 is provided with an elevator 6B which is movable in the vertical direction of the console 2, a tape cassette which is mounted on the elevator 6B, takes a tape cassette in and out of the shelf 6A, and a tape streamer which is in contact with the tape streamer 3. Hand block 6C for putting in and out
And are arranged. In the tape cassette applied to the tape streamer 3 according to this embodiment, a non-contact type IC tag is arranged on the back surface,
A reader / writer that accesses the IC tag is arranged on the shelf 6A and the elevator 6B.

FIG. 2 is a block diagram showing the CPU unit 5 together with peripheral components. In the CPU unit 5,
The host computer interface (host computer IF) 5A is, for example, a SCSI (Small Computer S).
The host computer 8 is connected to the host computer 8 by a system interface, and takes in commands and data to be recorded from the host computer 8 and outputs them to the internal bus BUS. Status data, reproduced data, and the like are output to the host computer 8.

The streamer interface (streamer IF) 5B is connected to the tape streamer 3 by, for example, SCSI, and outputs predetermined control commands output to the bus BUS and data to be recorded to the tape streamer 3, and vice versa. The status data output from the tape streamer 3 and the reproduced data are received from the tape streamer 3 and output to the internal bus BUS.

The control panel 5D is a console 2
And receives various operations by the operator, and notifies the CPU 5C of the operations by the operator via the internal bus BUS. The driver 5E drives the elevator 6B and the hand block 6C under the control of the CPU 5C.

The CPU 5C controls a whole operation of the backup system 1 in response to a command from the host computer 8 by securing a work area in the memory 5F and executing a predetermined processing procedure. That is, when an access command is input from the host computer 8, it instructs the tape streamer 3 to record and reproduce a tape cassette. At this time, if the access command from the host computer 8 is for a tape cassette different from the tape cassette loaded in the tape streamer 3, the transport mechanism 6 is controlled to load the corresponding tape cassette into the tape streamer 3. When a format of a so-called virgin tape is instructed by the operator, the tape cassette is loaded into the tape streamer 3 under the control of the transport mechanism 6, and the tape streamer 3 is instructed to perform an initialization process.

(1-2) Configuration of Tape Streamer FIG. 3 is a plan view showing the front and back of the tape streamer 3. The tape streamer 3 has an insertion port 3A formed in the front (FIG. 3A) so that a tape cassette can be inserted into and discharged from the insertion port 3A. The tape streamer 3 is provided with connectors for various connections on the back surface, so that the tape streamer 3 can be directly connected to the host computer 8 without the CPU unit 5, for example.

(1-2-1) Format of Tape Streamer FIG. 4 is a schematic diagram showing a format of a recording track by the tape streamer 3. Tape Streamer 3
In (2), longitudinal tracks are respectively formed above and below the magnetic tape 10, and oblique tracks are formed between the longitudinal tracks. Here, one of the upper and lower longitudinal tracks is assigned to the controller track 10A, and a control signal for tracking control is recorded. The other longitudinal track is ID track 1
0B, and information for managing the diagonal track is recorded in a management table.

On the other hand, an oblique track is formed by sequentially arranging a set of recording tracks with positive and negative azimuth angles. Each diagonal track is formed so as to be divided into two by a substantially central portion, and a preceding recording track of a set of recording tracks has a tracking control part for tracking control at this central divided portion. An area TP in which a pilot signal is recorded is formed.

Further, as for the diagonal track, one track set is formed by two sets and four recording tracks, and this track set is formed as a unit. A track set ID used for identifying each track set is set in each track set, and this track set ID is assigned to a part of information to be recorded on the ID track 10B. As the track set ID, a physical track set ID that simply increases in all track sets and a logical track set ID that simply increases except for dummy, EOD, and the like are set. The track set ID is S
The time code is converted into a time code by MPTE and recorded on the ID track 10B.

Each diagonal track is assigned to the A track, B track, C track, and D track corresponding to each channel of the recording / reproducing system from the leading side of the track set.

The track set includes a user track set used for recording user data, a tape mark track set assigned to a tape mark indicating a file delimiter, and an EOD (End Of D) indicating an end of data.
ata) A distinction is made between a track set, a dummy track set forming a dummy track, and the like.

FIG. 5 is a schematic diagram showing the relationship between the track set thus formed and the ECC block which is an error correction processing unit. The tape streamer 3 divides user data or the like to be used for recording in predetermined block units and adds an error correction code to form an ECC block. In the tape streamer 3, data of eight ECC blocks is allocated to one track set. At this time, each of the ECC blocks indicated by the numerals 0 to 7 is divided into four equal parts in the direction of outer parity and assigned to each track, whereby the tracks are interleaved and recorded. In the data allocated to each track, the arrangement is changed and the data is subjected to word interleave processing and recorded.

FIG. 6 is a schematic diagram showing the ECC block. One ECC block is assigned user data of 77 × 190 bytes, and a 27-byte outer parity is generated for a 77-byte data string, and this outer parity is added to the data string. After an additional 2 × 104 byte block ID is added,
Block I in the direction orthogonal to the outer parity
A 12-byte inner parity is generated for a 192-byte data string including D, and the inner parity is added to the data string.

Thus, the ECC block is formed by adding a product code type error correction code and further adding a 4 × 104 byte synchronization pattern SYNC. Here, the block ID is an identification ID of the ECC block, and the synchronization pattern SYNC is a specific pattern indicating the start of the ECC block.

As a result, in the tape streamer 3, 7
One ECC block is formed by allocating 7 × 190 bytes of user data and the like, and eight ECC blocks are further formed.
The assignment of blocks to one track set results in 1170 in one track set.
40 bytes of user data and the like can be assigned.

FIG. 7 is a schematic diagram showing the data structure of 117040 bytes allocated to this one user track set. One track set has a format ID of 4 bytes at the beginning. Here, the format ID is an ID for format identification, and in this embodiment, a value FFFF0000h indicating that user data is recorded in a track set of four tracks.
Is described.

Subcodes are allocated to the following 136 bytes, tables such as VSIT, VIT, and BST described later, user data track sets, identification data of tape mark track sets, and logical track set IDs.
Etc. are assigned data for track set management,
A logical track set ID and the like are recorded.

The number of bytes obtained by subtracting the data length of the block management table from the subsequent 116884 bytes is allocated to recording of user data and the like. When assigning user data to this area, if the area cannot be filled with user data, dummy data is assigned.

The block management table is set to a maximum of 4096 bytes. Here, the tape streamer 3 is configured to be able to record and reproduce data in units of blocks of a set of track sets, and the block management table records a table used for managing these blocks. Further, in the track set, the next 12 bytes are allocated to reservation, and the remaining 4 bytes are allocated to EOD (End Of Data) indicating the end of one track set.

The tape streamer 3 records user data using a track set as a basic unit in this way, and records various management data.

FIG. 8 is a schematic diagram showing the entire layout of the magnetic tape 10. The magnetic tape 10 is a physical magnetic tape 10 excluding a leader tape connected to a reel.
A recording start position LBOT (Logical Beginning Of Tape) is set on the side on which the magnetic tape 10 has traveled a predetermined distance from the beginning PBOT (Physical Beginning Of Tape), and a similar physical end PEOT (Physical End Of Tape).
f Tape), a recording end position LEOT (Logical End Of Tape) is set on the scanning start end side of the magnetic tape 10.
Various data are recorded on the magnetic tape 10 between the recording start position LBOT and the recording end position LEOT, so that the magnetic tape 10 is used in a region near the leader tape where the error rate is relatively easy to deteriorate. . The magnetic tape 10 forms one physical volume between the recording start position LBOT and the recording end position LEOT.

The magnetic tape 10 has a recording start position LBOT
A run-up area is formed for a predetermined distance, and the magnetic tape running system can be servo-locked in the run-up area. Therefore, the magnetic tape 10
Oblique tracks are sequentially formed from this run-up area.

On the magnetic tape 10, a VSIT (Volume Set Table) is recorded following the run-up area, and the first physical track set ID for recording the VSIT is set to 0ID. Here, in the VSIT, various data for managing the logical volume between the recording start position LBOT and the recording end position LEOT are recorded. That is, VS
The IT records the volume name of the magnetic tape, the number of recorded files, each file name, the physical track set ID of the VIT assigned to each file, and the like, whereby the tape streamer 3 accesses the VSIT. Thus, each file recorded on the magnetic tape 10, the recording position of each file, and the like can be confirmed. Here, one VSIT is formed by one track set (1 ID), and the same content is repeatedly recorded ten times to ensure high reliability.

On the magnetic tape 10, a VSIT retry area for 90 IDs is formed following the VSIT recording area. If necessary, the VSIT is re-recorded in this retry area, and the recovery processing is performed. It has been made executable.

Further, in the magnetic tape 10, a position margin band is subsequently formed for a predetermined ID, so that even if the VSIT is updated, the recorded data in the subsequent area is not affected at all. The magnetic tape 10
The area between the position margin band and the recording end position LEOT is allocated to the area of the logical volume.

FIG. 9 is a schematic diagram showing logical volumes assigned to this logical volume area. In the magnetic tape 10, data is recorded in file units with a tape mark TM being a file delimiter code interposed therebetween (FIG. 9A), and each file is configured by blocks. (FIGS. 9 (B) and (C)).

In the tape streamer 3, the DIT (Directory Information Table) and E
A unit including an OD (End Of Data) constitutes one logical volume. Here, the DIT is a table for managing one logical volume to which the DIT is allocated, and one length is formed by 40 IDs. DIT
As shown in FIG. 9 (D), the same content by this 40 ID is repeatedly recorded seven times, so that high reliability can be ensured.

Each DIT is assigned the run-up area described above with reference to FIG. 8, so that the servo system can be locked. Subsequently, a position margin band is arranged on the rear side so that, similarly to the VSIT, even if updated, the recorded data in the subsequent area is not affected at all.

DIT, as shown in FIG.
VIT (Volume Information Table) by D, 1ID
(Bad Spot Table) by LID, LID by 1ID
T (Logical ID Table), FIT by 20 ID (File
Information Table), 1ID UIT (User Inf)
ormation Table) is set. The DIT is set so that the remaining 16 IDs are reserved.

In the VIT, the physical track set ID is recorded in the VSIT, whereby the VIT can be accessed with reference to the VSIT recording, and the entire DIT can be accessed. In the VIT, a logical track set ID is set so as to match the physical track set ID. VI
As shown in FIG. 10, T is assigned the volume label of the logical volume to which the DIT is assigned, the first physical track set ID of the user track set, and the last physical track set ID.

The BST is assigned position information of an area (hereinafter referred to as a bat spot) which is set to be unusable by the tape streamer 3 due to a scratch or the like on the magnetic tape 10. That is, in the tape streamer 3, when a bit error that is difficult to correct is generated by the read-after-write and retry processing at the time of recording, the data after this area is recorded again on the magnetic tape. In the tape streamer 3, for data newly recorded on the magnetic tape in this manner, an area where this data should be originally recorded is defined as a bad spot. In the BST, the physical track set ID at the start end and the physical track set ID at the end of such a bad spot are recorded.

The LIDT (Logical ID Table) is used for a high-speed search for each block, and as shown in FIG.
For each logical track set ID, data of a file number, a physical track set ID, and a block number are recorded. As a result, the tape streamer 3 can roughly detect the position of the block to be accessed and search for the head at a high speed.

The FIT is formed by recording a physical track set ID of a tape mark and a block number of each block as shown in FIG. UT is information indicating whether or not the volume has been updated, and status data indicating whether or not the volume has been updated is set to FFFFFFFFh before the update,
After updating, it is set to 00000000h.

FIG. 13 is a diagram showing the relationship between the VSIT and the like in the physical volume and the logical volume. In the tape streamer 3, the user data is recorded on the magnetic tape and recorded on the magnetic tape according to this configuration. It is designed to reproduce user data.

(1-2-1) Schematic Configuration of Tape Streamer FIG. 14 is a block diagram showing the tape streamer 3 according to such a format. Tape Streamer 3
In the SCSI interface (SCSIIF)
Reference numeral 21 is connected to the CPU unit 5 by a SCSI interface, and is directly connected to the host computer when the CPU unit is not used. SCSI
The interface 21 inputs user data to be recorded and outputs it to the memory controller 22, and outputs reproduced data output from the memory controller 22 to the host computer. The SCSI interface 21 notifies a command from the CPU unit 5 and the host computer 8 to the main CPU 23 via the memory controller 22. Conversely, it receives status and the like output from the main CPU via the memory controller 22 and outputs this status and the like to the host computer 8 and the CPU unit 5.

The memory controller 22 temporarily stores user data input via the SCSI interface 21 in the buffer memory 24, and further stores the data stored in the buffer memory 24 in accordance with the processing of the subsequent ECC encoder (ECCENC) 25. Output according to timing. Note that the memory controller 22 inputs the data of the block management table, the corresponding data such as the DIT, and the like from the main CPU 23, temporarily stores the data in the buffer memory 24, and outputs the data to the ECC encoder 25. Conversely, during playback, the memory controller 22
Temporarily stores the user data output from the ECC decoder (ECCDEC) 26 in the buffer memory 24 at a timing synchronized with the processing of the ECC decoder 26, and further stores the stored user data in the SCS.
Output to the I interface 21. In addition, DI
In the case of T or the like, the data output from the ECC decoder 26 is output to the main CPU 23. The error detection result input together with the user data is notified to the main CPU 23 by accessing the main CPU 23.

The buffer memory 24 processes user data sequentially input in a bank structure in units of a capacity corresponding to the above-mentioned predetermined number of track sets.
This constitutes a bank memory. As a result, in the tape streamer 3, the recording / reproducing process is executed and the retry process is executed using one bank configured in the buffer memory 24 as a processing unit. As a result, in a track set, when user data is recorded with a data amount less than one bank, a dermy track set in which dermy data is recorded instead of the user data is formed.

The ECC encoder 25 forms the ECC block described above with reference to FIG. 6 by generating and adding an error correction code to data output from the memory controller 22 and by adding a synchronization pattern and the like. Further, the ECC encoder 25 outputs the data of the ECC block by a plurality of systems corresponding to the arrangement of the magnetic heads. Further, at this time, the ECC encoder 25 outputs these data in a predetermined order, thereby executing inter-track interleaving and word interleaving processing.

The equalizer 28 converts data output from the ECC encoder 25 by a plurality of systems corresponding to the arrangement of the recording heads into a serial data string, and further modulates the data by a method suitable for recording on the magnetic tape 10. As a result, the equalizer 28 generates a drive signal for driving the recording head, and drives the recording head mounted on the rotating drum 29 with this drive signal.

The rotary drum 29 is provided with a recording head of a predetermined system and a reproducing head for scanning the scanning trajectory of the recording head, and rotates at a predetermined rotation speed under the control of the servo circuit 31. This enables Tape Streamer 3
Are formed so that diagonal tracks are sequentially formed on the magnetic tape 10 running at a predetermined speed to record user data and the like, and that the recording result can be monitored by a reproducing head.

The equalizer 30 receives a reproduction signal from a reproduction head mounted on the rotary drum 29 during recording and reproduction, and performs waveform equalization and demodulation processing on the reproduction signal to thereby record data recorded on the magnetic tape 10. To play.

The ECC decoder 26 uses the equalizer 3
The output data of 0 is fetched, and error correction processing is performed using an error correction code added during recording. ECC decoder 2
6 outputs the user data and the like obtained by the error correction processing to the memory controller 22 together with the error detection result as the error correction processing result. This allows the tape streamer 3 to output the data recorded on the magnetic tape 10 to the host computer 8 via the buffer memory 24, and to obtain data such as VSIT by the main CPU 23 as necessary.

Further, the ECC decoder 26 notifies the main CPU 23 of the error detection result obtained in this way via the buffer memory 24.
Under the control of 23, processing such as retry can be executed as needed. The ECC decoder 26
When the user data is recorded, the error detection process is simply executed, and the resulting error detection result is recorded in the buffer memory 24 together with the user data and the like, thereby being recorded in the read-after-write process. It is possible to determine whether data has been correctly reproduced. The ECC decoder 26 stores such an error detection result in the buffer memory 24 by setting a corresponding error flag.

In doing so, the main CPU 23 secures a work area in the random access memory (RAM) 33 and executes a central processing unit that executes a predetermined processing procedure in response to a command input via the SCSI interface 21. Mainly composed of this tape streamer 3
It controls the overall operation and notifies the host computer 8 of the status as required. In this process, the buffer memory 24 is accessed as necessary to obtain information such as VSIT and DIT reproduced from the magnetic tape 10, and further, based on this information, the operation of the drive system and the like of the magnetic tape 10 is controlled. I do. After recording the user data, the entire operation is controlled so that the corresponding DIT and VSIT are rewritten.

System controller (syscon) 34
Controls the operation of the mechanical system of the tape streamer 3 by exchanging data with the main CPU 23 executed through a dual port RAM (DP-RAM) 35. That is, in the tape streamer 3, the sensor 37 is disposed at a cassette insertion port or the like, and detects, for example, whether or not the magnetic tape 10 can be loaded, and notifies the servo circuit 31 of the detection. The capstan motor (M) 36 runs the magnetic tape 10 under the control of the servo circuit 31. The fixed head 38 forms the longitudinal tracks 10A and 10B of the magnetic tape 10 and outputs a reproduction signal of the longitudinal tracks 10A and 10B to the servo circuit 31.

The servo circuit 31 drives a predetermined drive system based on the detection result of the tape cassette by the sensor 37 to execute processing such as loading and unloading of the tape cassette, and loading and unloading of the magnetic tape 10. And the like. The servo circuit 31 drives the rotary drum 29 to rotate, and controls the rotation speed of the capstan motor 36 based on the determination of the reproduction result of the CTL track 10A based on the rotation phase of the rotary drum 29, thereby performing tracking control. Execute the processing of During reproduction, the servo circuit 31 executes these tracking control processes with reference to a tracking control pilot signal assigned to an oblique track of the magnetic tape 10.

On the other hand, when the magnetic tape 10 is initialized, the servo circuit 31 drives the fixed head 38 while the magnetic tape 10 is running at a predetermined running speed, so that the magnetic tape 10 10A and 10
Form B. The servo circuit 31 includes a fixed head 38
The obtained reproduction signal is processed to reproduce the management data, and the management data is output to the system controller 34. The time code assigned to the management data is obtained from a time code recorder (TCR) 4.
Output to 0.

In this initialization process, the time code recorder 40 sequentially generates a time code and outputs it to the servo circuit 31. The servo circuit 31 uses the time code and various data output from the system controller 34. The management data is generated by the fixed head 3
8 is driven. On the other hand, at the time of recording and reproduction, the time code obtained from the servo circuit 31 is replaced with the track set ID.
And output.

The system controller 34 controls the operation of the servo circuit 31 and also outputs the track set ID output from the time code recorder 40 via the main CPU 23 to the ECC encoder 25 and the like.

Interface CPU (IFCPU) 4
1 exchanges data with the main CPU 23 via the DP-RAM 42, whereby the shelf 6 A, the elevator 6 B
Is capable of acquiring information of a tape cassette, and is further capable of performing data communication with another computer system.

That is, in the tape streamer 3, the reader / writer arranged on the shelf 6A or the like uses the antenna (AN
T) 44 to I located on the back of the tape cassette 45
A radio wave is transmitted to the C tag 46, and this radio wave
When a response is obtained from the IC tag 6, various information relating to the tape cassette 45 is transmitted to and received from the IC tag.

The display CPU 49 inputs and outputs data transmitted and received between the IC tags via the memory label interface 47 to and from the interface CPU 41. The display CPU 49 displays various data on a predetermined display screen according to data input via the interface CPU 41. This display is, for example, display of information on a tape cassette loaded in the tape streamer 3.

The SIO 50 is, for example, RS-232C,
It is a serial interface such as RS-422, and transmits and receives maintenance information to and from external devices. The Ethernet IO is an Ethernet (registered trademark) interface, and is connected to a predetermined network so that various information can be transmitted and received.

(1-2-1) Unloading Process FIG. 15 is a schematic diagram showing the configuration of the magnetic tape 10 relating to the loading and unloading processes. The magnetic tape 10 has unloading areas ARU0, ARU1, AR
U2, ARU3,... Are set (FIG. 15
(A)).

Here, the unloading area ARU
.., ARU1, ARU2, ARU3,... Are set when loading and unloading processing are performed.
This unloading area ARU0, ARU1, ARU
The track IDs adjacent to the ARUs 3, ARU3,... Are executed by setting the physical IDs of the start position and the end position by the main CPU 23 so as to have a size capable of reliably preventing the magnetic tape 10 from being damaged. You. Also, unloading areas ARU0, ARU1, ARU
2, ARU3,... Are unloaded at the position on the LBOD side where the adjacent track set due to the scratches on the magnetic tape 10 does not become difficult to reproduce, and then loaded and pre-rolled. , When the unloading areas ARU0, ARU1, ARU2, ARU3,... End, the tracking control system is formed with a length that can be reliably servo-locked.

The unloading areas ARU0, AR
U1, ARU2, ARU3,... Allocate a track set based on dummy data to a part so that the magnetic tape 10 can be accessed by starting the running of the magnetic tape 10 in this manner. It is configured by recording necessary information repeatedly.

Specifically, at the time of recording, each of the unloading areas ARU0, ARU1, ARU2, and A in the magnetic tape 10 is recorded on the basis of the physical ID recorded on the longitudinal track 10B.
At the start position of the set point in RU3,..., A track set (D) using dummy data is recorded for 20 IDs, then a track set (UL) using 1 ID unloading data and a track set (DIT) using 40 IDs DIT. ) Are repeatedly recorded 20 times, and the unloading areas ARU0, ARU1, ARU2, ARU3,... Are sequentially and sequentially created according to the length of 820 ID by repeating the unloading data and DIT (FIG. 15 ( A-1)). Thus, when recording the user data, the magnetic tape 10 also stores the unloading areas ARU0, ARU1, and ARU.
2, ARU3,... Are created. It should be noted that the DIT repeatedly recorded in this manner is 40 I by repeated recording in the same manner as described above with reference to FIG.
D minutes are recorded. In a track set for 20 IDs using dummy data, the user data recorded immediately before may be repeatedly recorded instead of the dummy data.

FIG. 16 is a table showing the unloading data. Unloading data is VSIT
Almost in the same way as the data assigned to the file, the position information of each file is recorded and formed. Specifically, the top ID and the last ID of the magnetic tape 10, the top I of each logical volume
D, the last ID, and the number of IDs (valid IDs) are recorded by physical IDs. Thus, the magnetic tape 10 can access a desired file by the unloading data without accessing the VSIT.

The magnetic tape 10 has the unloading areas ARU0, ARU1, ARU2, ARU intermittently in the middle of the logical volume area of the magnetic tape 10.
By creating 3,..., The magnetic tape 10 can be loaded and unloaded at a position other than the beginning or end of the magnetic tape 10. Further, unloading areas ARU0, ARU1, ARU2, and ARU in which loading and unloading can be performed at locations other than the beginning or end of the magnetic tape 10.
According to the settings of 3,..., Predetermined data is recorded on the magnetic tape 10 in the IC tag 46 arranged on the tape cassette 45.

The magnetic tape 10 repeats the recording of the user data, and unloading areas ARU0 and ARU other than the head or end of such a magnetic tape 10.
When loading and unloading using 1, ARU2, ARU3,..., The VS recorded on the top side
It is conceivable that the IT is left without being updated, and in this case, consistency between the VSIT and the unloading data is lost. Therefore, in the tape streamer 3, a process for updating the VSIT of the magnetic tape 10 to achieve consistency is separately performed by an operation of the operator.

The tape streamer 3 is capable of storing the unloading areas ARU0, ARU1, ARU2, and ARU created in this manner in accordance with the mode selection by the user.
3. When the next access to the magnetic tape 10 is performed,
Unloading areas ARU0, ARU1, ARU2, ARU that are considered to have the shortest access start time
.. Are selected, and the magnetic tape 10 is unloaded in the selected unloading areas ARU0, ARU1, ARU2, ARU3,.

That is, when the user selects the mode in which the average access time of each file is minimized, the tape streamer 3 determines the end of the file recorded on the magnetic tape 10 and the start of the logical volume of the magnetic tape 10. The unloading area closest to the intermediate position from the position (the unloading area AR in FIG. 15A)
The unloading process is executed by rewinding the magnetic tape 10 to U1), so that, at the next access, even if any part of the magnetic tape 10 is accessed, the average access time as a whole is minimized. It can be so.

On the other hand, if the mode that minimizes the access time by the link recording is selected, the tape streamer 3 sets the unloading area closest to the end of the file recorded on the magnetic tape 10 (FIG. A)
In, the magnetic tape 10 is rewound to the unloading area ARU3), and the unloading process is executed, thereby making it possible to minimize the access time at the time of the next continuous recording.

On the other hand, some application programs in the host device can specify a file to be accessed next time to some extent. When the mode that minimizes the access time of the file specified by the host device is selected, the tape streamer 3 rewinds the magnetic tape 10 to the unloading area closest to the head of the file specified by the host device, and unloads the tape. When the loading process is executed and the file to be accessed next by the host device can be specified or predicted, the access time of the file can be minimized.

In the magnetic tape 10, the unloading areas ARU 0, ARU 1, ARU 2, ARU 3,..., Which are set at a certain position on the magnetic tape 10, are recorded on the magnetic tape 10. An unrecorded area following the end (EOD) of the file is separately set as a setting location of the unloading area AR (FIG. 15).
(B)). The magnetic tape 10 is instructed by the user for first unloading, and the unloading areas ARU0, ARU1, ARU2, ARU3,.
When it is determined that the unloading by the set position of the unloading area AR of the unrecorded area can be performed in a shorter time than the unloading area in the unloading area A, the unloading area A
An unloading area AR is formed at the position where R is set, and the unloading process is performed. As a result, the magnetic tape 10 can be unloaded in a much shorter time than before.

Further, in the magnetic tape 10, the last file, EOD,
When the unloading area AR formed on the back side of the tape is connected to the immediately preceding file and recorded, the unloading area AR is set to the unloading area ARU0, ARU set at a certain position on the magnetic tape 10.
.., ARU2, ARU3,..., When they are formed in substantially the same place as any of the formation places, a connection recording process is executed following the unloading area AR,
As a result, the unloading areas AR formed for the first unloading are formed on the magnetic tape 10 at a constant pitch.
RU1, ARU2, ARU3,...

On the other hand, the unloading area A
R is an unloading area ARU0, ARU1, ARU2, ARU set at a fixed location on the magnetic tape 10.
If the track is not formed at the same location as any of the locations 3, 3,..., The unloading area AR is erased by overwriting, leaving the predetermined number of track sets by dummy data, and the user data is deleted. Be recorded.

FIG. 17 shows the state of the unloading area AR.
9 is a flowchart showing a processing procedure of the main CPU 23 relating to the creation of a file. In the tape streamer 3, when the magnetic tape 10 is accessed by normal loading, when the tape cassette is loaded, the magnetic tape 10 is pulled out from the tape cassette and placed on the magnetic tape traveling system. Start and FIG. 18 (A)
As shown by the arrow A, the VSIT recorded at the head of the magnetic tape 10 is reproduced. Furthermore, this VSI
DIT corresponding to the access command of the host device from T
For example, when the access command is a command for reproducing a predetermined file, the DIT of the corresponding file is accessed according to the record of the reproduced VSIT, and then, according to the record of the DIT, as indicated by an arrow B. Access the specified file.

When such an access is completed, for example,
The tape streamer 3 receives an unloading instruction from the host device, and in this case, the main CPU 2
3 moves from step SP1 to step SP2, and determines whether or not this unloading instruction is due to first unloading. If a negative result is obtained here, the main CPU 23 proceeds to step SP3 and starts normal unloading processing. That is, the main CPU 23 sends the magnetic tape 1 to the run-up area before the VSIT in accordance with an instruction to the system controller 34.
In step SP4, the magnetic tape 10 is drawn into the tape cassette in the run-up area, and then the tape cassette is ejected. Thereafter, the main CPU 23 ends this processing procedure in a succeeding step SP5. At this time, when the user data is recorded on the magnetic tape 10, for example, the tape streamer 3
In order to ensure consistency with the corresponding DIT and VSIT, the corresponding DIT is located and the DIT is updated, and then the VSIT is located and the VSIT is updated.

On the other hand, when fast unloading is instructed by the host device, the main CPU 23
Is obtained by obtaining a positive result in step SP2,
Move to step SP6, where the physical ID from the current position to the immediately preceding unloading area and the EO from the current position
By comparing the unloaded data and DIT with the physical ID up to D, the nearest recordable portion is detected.

If the current position is close to the immediately preceding unloading area, the main CPU 23 proceeds to step SP6.
From step SP7 to step SP7, and as shown in FIG.
After rewinding 0, the unloading area is updated, and the routine goes to step SP8.

On the other hand, if the current position is close to the EOD, the main CPU 23 proceeds from step SP6 to step SP9, finds the EOD, as shown in FIG. Is recorded, the unloading data and DIT are repeatedly recorded to create the above-described unloading area AR, and the routine goes to step SP8.

The main CPU 23 determines in step SP8
In FIG. 19A, when loading the magnetic tape in the magnetic tape traveling system and starting the traveling of the magnetic tape at the time of loading, the tracking control system operates at least at the end of each unloading area. The magnetic tape 10 is rewound within the range of the length of the unloading area so that the magnetic tape 10 can be locked and the unloading area remains at the leading end of the magnetic tape 10 with a sufficient length.

The main CPU 23 starts the running of the magnetic tape during the subsequent loading, selectively fetches data to be correctly reproduced from the unloading area, and constructs the DIT, whereby the tracking control system is servo-locked. At this point, the acquisition of DIT data has already been completed.

That is, as shown in FIG. 19B, when the reproduction of the magnetic tape 10 is started from the position rewound in this way, immediately after the start of the reproduction, the magnetic tape 1
Since the traveling speed of 0 gradually increases,
In a tape streamer, it is difficult to scan each track set correctly.
As shown by the mark, indicates the error due to the error correction result,
It becomes difficult to correctly reproduce any DIT.

However, as the running speed of the magnetic tape 10 increases after the start of running of the magnetic tape 10, the number of track sets to be reproduced correctly gradually increases, and eventually the tracking control system performs servo lock. At this point (FIG. 19C), data can be correctly reproduced from almost all track sets. In this case, since the magnetic tape 10 does not require so-called run-in processing, the magnetic tape 10 is drawn out of the tape cassette and the running of the magnetic tape is started simply by moving the magnetic tape 10.
By being able to acquire the IT, the time required for starting the access can be shortened accordingly. Conventionally, the magnetic tape 10
Is set on a magnetic tape traveling system, the magnetic tape is rewound for so-called running, and the magnetic tape 10 is made to travel (so-called pre-roll).
In this embodiment, the access can be made in a short time because the pre-roll processing is unnecessary. In addition, by constructing a DIT by selectively acquiring data, it is possible to shorten the time during which access is possible.

Also, in this case, since the unloading area is left with a sufficient length also at the head side, it is possible to prevent the unloading and damage of the user track set due to the loading.

After rewinding the magnetic tape 10 by a predetermined distance in this way, the main CPU 23 proceeds from step SP8 to step SP10 and records on the IC tag 46 that the tape cassette is related to the first unloading. After transmitting the control command to the reader / writer to perform the operation, the process proceeds to step SP4, where the magnetic tape 10 is pulled into the tape cassette, and the tape cassette is discharged. Thereafter, the main CPU 23 proceeds to step SP
Then, the procedure goes to 5 to end this processing procedure.

FIG. 20 is a flow chart showing the loading process of the tape cassette thus ejected. When the transport mechanism 6 transports the tape cassette 45 to the cassette insertion slot, the main CPU 23 pulls in the tape cassette by exchanging data with the servo circuit 31. In this state, when loading is instructed by the host device, the main CPU 23 proceeds from step SP21 to step SP22, where the main CPU 23 controls the operation of the reader / writer to acquire the record of the IC tag 46.

Subsequently, the main CPU 23 proceeds to step SP
23, it is determined based on the data obtained from the IC tag 46 whether or not this tape cassette is the result of the first unloading. If a negative result is obtained here, the process proceeds from step SP23 to step SP24, where normal loading is performed. Execute the process. That is, in this case, the DIT and VSIT are updated, and the magnetic tape 10 is rewound and ejected.
3, as described above with reference to FIG. 18A, after the magnetic tape is pulled out from the tape cassette and placed on the magnetic tape traveling system, VSIT and DIT are sequentially accessed, and the subsequent step SP is performed based on the data obtained by this access.
The access to the file specified in 25 is started, and the process proceeds to step SP26 to end this processing procedure.

On the other hand, when this tape cassette is a tape cassette related to first unloading,
The main CPU 23 proceeds from step SP23 to step S23.
In P27, the magnetic tape 10 is pulled out of the tape cassette and set in the magnetic tape traveling system. Subsequently, the main CPU 23 proceeds to step SP28, and starts running the magnetic tape under the control of the system controller 34. The main CPU 23 simultaneously instructs the start of tracking control by the tracking control system,
Reproduction data output from the C decoder 26 is selectively taken in based on an error flag added to each data. Accordingly, the main CPU 23 starts building the DIT based on the data that is correctly reproduced when the magnetic tape starts running, and at least at the time when the tracking control system completes the scanning of the unloading area, which is the time when the servo lock is completed, The construction of the DIT data can be completed.

In this way, when starting the construction of the DIT data in this way, the main CPU 23 moves from step SP28 to step SP29 and waits for the completion of the construction of the DIT data. When the construction of the DIT data is completed, the main CPU 23 proceeds to step SP25. Then, the access according to the command of the host device is started. Thereby, the main CPU 23
Starts the running of the magnetic tape 10 without pre-rolling, and completes the acquisition of data necessary for accessing the magnetic tape 10 when the tracking control system servo-locks. When the access to the magnetic tape 10 is started, the access to the magnetic tape 10 can be started in a much shorter time than before.

(2) Operation of the First Embodiment In the configuration described above, in the backup system 1 (FIGS. 1 and 2), the tape cassette stored in the shelf 6A is controlled by the CPU unit 5 and the like. 3
, Then loaded and sequentially fixed head 3
8, the ID track 10B and the CTL track 10A, which are the longitudinal tracks of the magnetic tape 10, are recorded on the magnetic tape 10 (FIGS. 4 and 14). As a result, the track set ID based on the time code is recorded on the magnetic tape 10 as one of the management data in units of one track set. After that, after the magnetic tape 10 has been rewound, the V
The SIT is recorded (FIG. 8), whereby the volume name of the tape cassette is recorded, and the initialization process is completed. The tape cassette initialized in this way is
Under the control of the CPU unit 5, it is conveyed and stored at a predetermined position on the shelf 6A.

On the other hand, when data backup is instructed by the host computer 8, the CPU unit 5
When the tape cassette corresponding to the tape streamer 3 is not loaded, the corresponding tape cassette is taken out from the shelf 6A and set in the tape streamer 3. For the tape cassette loaded in the tape streamer 3, the tape streamer 3
And is stored in the shelf 6A.

When the tape cassette is loaded in the tape streamer 3 in this manner, the tape streamer 3 loads the magnetic tape to reproduce the VSIT, and the VSIT can access the file specified by the host computer 8. The magnetic tape 10 is run.

That is, when the first file is recorded on the magnetic tape 10, the DIT is recorded at a predetermined interval from the VSIT, and then the data output from the host computer 8 is sequentially recorded on the magnetic tape 10. In addition, when appending to a previously recorded file, the DIT of the corresponding file is reproduced with reference to the VSIT recording, the end of the last block is detected from this DIT, and input from the host computer 8 is sequentially performed from this end. Record the data to be recorded. When data reproduction is instructed from the host computer 8, the DIT of the corresponding file is accessed based on the VSIT recording, and the data recorded on the magnetic tape 10 is reproduced according to the DIT recording (FIG. 9). .

That is, at the time of recording, after adding an error correction code in a product code format to user data sequentially input by the ECC encoder 25 (FIG. 6), inter-track interleaving is performed by four tracks constituting one track set. 5 (FIG. 5) and are sequentially recorded on the magnetic tape 10 by interleaving between words. Further, the data is recorded on the magnetic tape 10 in units of banks set in the buffer memory 24.

At this time, in the tape streamer 3 (FIG. 12), four recording tracks formed on the magnetic tape 10 are set as one track set, and the bank control of the buffer memory 24 corresponds to one bank. For example, user data is sequentially recorded in units of eight track sets. Also, a logical ID whose value sequentially increases in the track set allocated to the user data is set in each track set so that each track set can be specified, and the user data is recorded.

In this recording process, when the tape streamer 3 records user data for a predetermined distance, after recording dummy data, the tape streamer 3 repeats unloading data and DIT necessary for accessing the magnetic tape 10 for a predetermined distance. Recorded on the magnetic tape 1
0, intermittently, unloading areas ARU1,.
.. (FIG. 15) are created. As a result, the tape streamer 3 can be used even in portions other than the beginning and end of the magnetic tape 10.
In the unloading areas ARU1,..., The magnetic tape 10 can be unloaded and the tape cassette can be ejected, and accordingly, the magnetic tape 10 is rewound to the beginning or fast-forwarded to the end for unloading. As a result, it is possible to process a continuous tape cassette in a shorter time.

That is, in the unloading process using the unloading areas ARU1,..., When the average access time is prioritized, the EOD, which is the end of recording user data, and the BOD, which is the recording start end of magnetic tape, The unloading area at a substantially intermediate point between the two is selected and the unloading process is executed. As a result, the tape streamer 3 can minimize the average access time when the next access destination is unknown or the like, and can accordingly shorten the access time as compared with the related art.

On the other hand, some host devices can predict the file to be subsequently accessed. In this case, the unload area is set so that the file specified by the host device can be accessed in the shortest time. The selection is made and the unloading process is executed. Thus, the tape streamer 3 can minimize the access time when the next access destination can be grasped by the host device, and can shorten the access time as compared with the related art. .

On the other hand, in the case of connection recording or the like, the head unloading area closest to the EOD is selected, and the unloading process is executed.
In this case, the tape streamer 3 can also minimize the access time in the case where the next access destination can be recognized by the host device, thereby shortening the access time as compared with the related art. can do.

On the other hand, when first unloading is instructed from the host device, the tape streamer 3 sets the unloading data closest to the current position to
An area where DIT can be recorded is selected. In this case, the tape streamer 3 has the unloading area A described above.
The magnetic tape is rapidly fed to the unloading areas ARU1,... Where the RU1,... Are closest to the current position, and the unloading processing is executed by updating the unloading areas ARU1,. On the other hand, when the current position is close to the unrecorded area on the tail side, the magnetic tape is fast-forwarded to the EOD on the tail side, an unloading area AR is created following this EOD, and the unloading process is executed. You. Thereby, the tape streamer 3 simply intermittently unloads the unloading area AR1,
The time required for unloading can be further reduced as compared with the case where... Are created.

In the tape streamer 3, the unloading area AR created following the EOD in this manner is
When the unloading area AR1, which is intermittently created on the magnetic tape 10, is close to any of the created locations, the unloading area AR is used in the splicing recording.
Then, user data and the like are recorded, and thus the unloading area AR is used as the original unloading areas AR1,.

On the other hand, the unloading area AR
Is created at a position that is greatly shifted from the original unloading area AR1,..., User data and the like are overwritten and recorded in the unloading area AR in the splicing recording. Will be erased. This enables Tape Streamer 3
Is designed to prevent a decrease in the recording capacity due to such an increase in the unloading area AR when repeatedly connecting and recording on the magnetic tape 10.

In the tape streamer 3, such unloading areas AR1 and AR contain unloading data, DIT, which is data necessary for accessing the magnetic tape.
Are repeated, and the unloading area is further updated and created. After the magnetic tape 10 is rewound by a predetermined distance, the unloading process is executed.

In the tape streamer 3, the rewinding distance is such that the magnetic tape starts running without pre-rolling at the time of loading, and the tracking control system can servo-lock at least at the end of each unloading area. It is set to a distance that is long enough to prevent damage due to loading and unloading of the user track set on the leading side of the magnetic tape 10, thereby providing much more access than before. The time required to start is reduced.

That is, when the tape streamer 3 is rewound in this way, the magnetic tape 10 is stored in the tape cassette and the tape cassette is ejected. At this time, the identification data relating to the first unloading is recorded on the IC tag of the tape cassette. Is done.

At the time of loading of the magnetic tape, the tape streamer 3 determines whether or not the tape cassette is for the first unloading based on the recording of the IC tag.
If the tape cassette is not a tape cassette related to the first unloading, the loading process is executed on the head side of the magnetic tape 10 as usual, and VSIT and DIT are sequentially reproduced.

On the other hand, in the case of the tape cassette related to the first unloading, the tape streamer 3
When the magnetic tape is pulled out from the tape cassette, the pre-roll processing is omitted and the reproduction of the magnetic tape is started.
Unloading data obtained from the C decoder 26,
Of the DIT playback data, the correctly played back data is selectively taken into the main CPU 23. Here, in the tape streamer 3, when the running of the magnetic tape 10 is started, the running speed of the magnetic tape 10 gradually increases, and the tracking control system locks to form a just tracking state, which is almost recorded on each recording track. The data will be played correctly. From the start of the following movement of the magnetic tape to the rising of the steady running speed, the data to be reproduced correctly increases as the running speed of the magnetic tape approaches the steady speed.

Thus, the tape streamer 3 selectively takes in the data reproduced correctly immediately after the running of the magnetic tape 10 without immediately rising to the steady speed and waiting for the servo lock, and performs DIT and unloading. By constructing the data, at least at the time when the servo system is locked, the fetching of the DIT and the unloading data can be already completed, and the time required to start the access to the magnetic tape 10 is shortened as compared with the related art. It has been made possible.

(3) Effects of the Embodiment According to the above configuration, it is possible to acquire information necessary for accessing a magnetic tape by selectively acquiring data to be correctly reproduced before loading and performing servo lock. By doing so, the time required to start accessing the magnetic tape can be further shortened as compared with the related art.

By setting the information necessary for accessing such a magnetic tape in the unrecorded area following the end of the recording of the user data, the time required for unloading can be shortened as compared with the related art. it can.

Further, by erasing the recording of the information necessary for accessing the magnetic tape created in this manner by overwriting the user data, it is possible to prevent a reduction in the recording capacity of the magnetic tape.

(4) Other Embodiments In the above-described embodiment, the unloading data and the DIT
However, the present invention is not limited to this case. On the contrary, the DIT is arranged at the head side, and the unloading data and the DIT are alternately recorded. Is also good.

In the above-described embodiment, the case where the unloading area is arranged at regular intervals on the magnetic tape and the unloading area is recorded in the unrecorded area following the EOD has been described. The present invention is not limited to this, and the time required for starting the access in the joint recording can be shortened even if the unloading area is recorded only in the unrecorded area following the EOD if necessary.

Also, in the above-described embodiment, a case has been described in which one track set is constituted by four tracks. However, the present invention is not limited to this, and one track set is used in units of a plurality of tracks other than four tracks. It can be widely applied to a case where a track set is configured.

In the above embodiment, the case where the present invention is applied to the tape streamer in combination with the transport mechanism has been described, but the present invention is not limited to this.
For example, the present invention can be widely applied to a tape streamer configured to be directly connected to a host computer.

In the above-described embodiment, the case of recording data of a computer has been described. However, the present invention is not limited to this, and can be widely applied to, for example, processing of video signals and audio signals. .

[0123]

As described above, according to the present invention, it is possible to acquire information necessary for accessing the magnetic tape by selectively acquiring data to be correctly reproduced before loading the servo lock during loading. In addition, the time required for starting access to the magnetic tape can be further shortened as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a backup system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the backup system of FIG. 1;

FIG. 3 is a front view and a rear view showing a tape streamer of the backup system of FIG. 1;

FIG. 4 is a schematic diagram illustrating a recording format by the tape streamer of FIG. 3;

FIG. 5 is a schematic diagram for explaining inter-track interleaving in the tape streamer of FIG. 3;

FIG. 6 is a schematic diagram illustrating an ECC block in the tape streamer of FIG. 3;

FIG. 7 is a schematic diagram for explaining a track set in the tape streamer of FIG. 3;

8 is a schematic diagram for explaining a physical volume of the entire magnetic tape in the tape streamer of FIG. 3;

9 is a schematic diagram for explaining each volume in the tape streamer of FIG. 3;

FIG. 10 is a chart showing VIT.

FIG. 11 is a chart showing LIDT.

FIG. 12 is a chart showing FIT.

FIG. 13 is a table showing a relationship between a physical volume and each track set.

FIG. 14 is a block diagram showing the tape streamer of FIG. 3;

FIG. 15 is a schematic diagram for explaining an unloading area in the tape streamer of FIG. 3;

FIG. 16 is a table showing unloading data.

FIG. 17 is a flowchart showing a processing procedure at the time of unloading in the tape streamer of FIG. 3;

FIG. 18 is a schematic diagram used for describing the processing procedure in FIG. 17;

FIG. 19 is a schematic diagram illustrating rewinding during unloading.

20 is a flowchart showing a processing procedure at the time of loading in the tape streamer of FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Backup system, 3 ... Tape streamer, 5 ... CPU unit, 6 ... Transport mechanism, 8 ... Host computer, 10 ... Magnetic tape, 23 ... Main CPU, 24 ... Backup memory, 25 ... … EC
C encoder, 26 ECC decoder

Claims (4)

[Claims] 1. A magnetic recording / reproducing apparatus for sequentially forming diagonal tracks on a magnetic tape drawn from a tape cassette by a magnetic head arranged on a rotating drum and recording desired user data. After repeatedly recording data necessary for accessing the magnetic tape in the nearest recordable portion, the magnetic tape is rewound by a predetermined distance within the range of the repeated recording, and the magnetic tape is mounted on the tape cassette. Wherein the predetermined distance is at least a distance from the time when the magnetic tape is pulled out from the tape cassette and the running of the magnetic tape is started until the tracking control system is servo-locked. Recording and playback device. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the closest recordable portion is an unrecorded area following the end of the recording of the user data. 3. The continuous recording according to claim 1, wherein the position of the repetitive recording is determined, and the repetitive recording is erased by overwriting the user data according to the determination result. Magnetic recording and reproducing device. 4. A magnetic recording / reproducing apparatus for reproducing desired data from a diagonal track of a magnetic tape stored and held in a tape cassette, wherein after the magnetic tape is pulled out from the tape cassette, the magnetic tape travels. At the same time, the tracking control by the tracking control system is started, and the selective capture of data correctly reproduced from the magnetic tape and the construction of data necessary for reproducing the magnetic tape with the captured data are started. By doing
At least at the time when the tracking control system completes the servo lock, the acquisition of data necessary for reproducing the magnetic tape is completed, and the magnetic tape is accessed based on the acquired data necessary for reproducing the magnetic tape. A magnetic recording / reproducing apparatus.