JP2001216740A - Data processor, data recording method and data reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably send user data to a host device even when an error occurs in data reproduced by applying a data processor, a data recording method and a data reproducing method to a tape streamer for backing up data of a server, etc. SOLUTION: This invention neglects an error by the continuity of the first identifier assigned to a recording track before and after a recording track where an error is detected and judgment of the attribute of an adjacent recording track, forms a recording track where unnecessary data is recorded in front and rear of the boundary of connect-writing, and neglects the error corresponding to the presence and absence of the identifier of connect-writing to the recording track where the error is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a data processing device,
The data recording method and the data reproducing method can be applied to, for example, a tape streamer for backing up data in a server or the like. The present invention ignores errors by determining the continuity of first identifiers assigned to recording tracks before and after a recording track in which an error is detected, and by determining the attribute of an adjacent recording track, so that tying is also possible. Before and after the boundary, by placing a recording track on which unnecessary data is recorded, and by ignoring the error based on the presence or absence of a linking identifier for the recording track on which the error was detected, an error is generated in the reproduced data. In this case, the user data can be reliably transmitted to the host device even when the error occurs.

[0002]

2. Description of the Related Art Conventionally, in a tape streamer,
By adding an error correction code and recording desired data at a high density, it is used for backup of a server or the like.

That is, in a tape streamer, data to be provided for backup is divided into predetermined blocks, and an error correction code in a product code format is generated. Further, the tape streamer outputs the data and the error correction code to the recording head in a predetermined order, and records the data on the magnetic tape while sequentially forming recording tracks diagonally on the magnetic tape. At this time, the tape streamer
The scanning trajectory of the recording head is scanned and read-after-written by the reproducing head, and so-called retry processing is executed for a portion where data cannot be reproduced correctly.

On the other hand, at the time of reproduction, a tape streamer sequentially reproduces data recorded on a magnetic tape by scanning a magnetic tape with a reproducing head and processing a reproduction signal, thereby correcting an error correction added at the time of recording. Error correction processing is performed using a code. Further, the retry process is repeated for the portion where the error correction processing is difficult to perform the error correction. Thus, the tape streamer can back up desired data with high reliability.

[0005]

In this type of tape streamer, an error is detected in units of a plurality of blocks and retry processing is executed. In these plurality of blocks, data other than user data is transferred. Includes records.

That is, in a tape streamer, dummy data may be recorded in place of user data. Even if such dummy data cannot be reproduced correctly, there is no effect on reproduction of user data. Absent. Even in such a case, if the retry process is repeated in units of a plurality of blocks, the retry process is uselessly repeated, and if the retry fails, the user data can be correctly reproduced. However, the transmission of the reproduced user data to the host computer is stopped.

[0007] Such a phenomenon is considered to increase as the recording density on the magnetic tape increases. For example, in the case of joint writing, it is considered that the phenomenon becomes remarkable at the jointed portion.

The present invention has been made in consideration of the above points, and a data processing device and a data recording method capable of reliably transmitting user data to a host device even when an error occurs in reproduced data. And a method of reproducing data.

[0009]

In order to solve the above-mentioned problems, the present invention is applied to a data processing device or a data reproducing method, and is applied to a data track before and after a recording track where an error is detected. Based on the determination based on the continuity of the first identifier assigned to the recording track and the second identifier set on the recording track adjacent to the recording track where the error was detected, the reproduction data was ignored ignoring the error detection. To process.

According to the invention of claim 2 or claim 6, the invention is applied to a data processing device or a data recording method,
A recording track on which unnecessary data is recorded is arranged before and after the boundary of the joint.

Further, in the invention of claim 4 or claim 7, the invention is applied to a data processing device or a data recording method,
Depending on the presence or absence of a linking identifier for the recording track where an error is detected, the reproduction data is processed ignoring the error detection.

According to the first or fifth aspect, the continuity of the first identifier assigned to the recording tracks before and after the recording track where the error is detected, and the recording adjacent to the recording track where the error is detected. According to the determination based on the second identifier set for the track, the attribute of the data recorded on the recording track where the error has occurred can be determined based on the first and second identifiers set at the time of recording. . Therefore, if the reproduction data is processed by ignoring the error detection by this determination, unnecessary data errors can be ignored, and even if an error occurs in the reproduced data, the user data can be reliably detected. Can be sent to the host device.

According to the second or sixth aspect of the present invention, a recording track on which unnecessary data is recorded is arranged before and after the boundary of the joint writing, thereby avoiding a portion where an error frequently occurs. Thus, even if an error occurs in data reproduced at a portion where an error frequently occurs, the user data can be reliably transmitted to the host device.

According to the fourth or seventh aspect of the present invention, if the reproduced data is processed ignoring the error detection based on the presence / absence of the linking identifier for the recording track where the error is detected, the linking is performed. Assuming that a recording track on which unnecessary data is recorded is formed before and after the boundary, user data can be reliably sent to the host device even if an error occurs in reproduced data.

[0015]

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 an embodiment of the present invention. This backup system 1
Is configured by arranging a tape streamer 3 and the like on a large console 2. That is, this backup system 1
The tape streamer 3, the power supply unit 4, and the CPU unit 5 are sequentially arranged from the lower side of the front, and the transport mechanism 6 of the tape cassette is arranged on the rear 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 tracks, 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 allocated 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 as 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 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 to be 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
IT is the volume name of this magnetic tape, the file name recorded on the magnetic tape, and the V assigned to each file.
The physical track set ID and the like of the IT are recorded, so that the tape streamer 3 can access the VSIT so that the magnetic tape 10 can be identified. Further, each file recorded on the magnetic tape 10 and the recording position of each file are recorded. And so on. Where VS
One IT 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 the retry area, and the recovery process and the like are 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 when 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 allocated 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 of the DITs 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 VIST, even when the data is updated, the recorded data in the subsequent area is not affected at all.

DIT is 1I, 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 on the basis of 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
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 high-speed search for each block, and data of a file number, a physical track set ID, and a block number is recorded for every 200 logical track set IDs. 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. The UT is information indicating whether or not the volume has been updated. Status data indicating whether or not the volume has been updated is set to FFFFFFFFh before updating and 000000 after updating.
00h.

(1-2-1) Schematic Configuration of Tape Streamer FIG. 10 is a block diagram showing a tape streamer 3 according to such a format. In the tape streamer 3, the SCSI interface (SCSIIF) 2
1 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. The SCSI 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. Further, the SCSI interface 21 notifies a command from the CPU unit 5 and the host computer 8 to the main CPU unit 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 the 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. The memory controller 22 inputs the data of the block management table, the above-mentioned DIT, and the like corresponding data from the main CPU unit 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 2
2 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 SC
Output to SI interface 21. In addition, D
In the case of IT or the like, data output from the ECC decoder 26 is output to the main CPU unit 23. The error detection result input together with the user data is notified to the main CPU unit 23 by accessing the main CPU unit 23.

The buffer memory 24 processes user data sequentially input in a bank structure in units of 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 the data output from the ECC encoder 25 into a serial data string by a plurality of systems corresponding to the arrangement of the recording heads, 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 rotating 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 rotational 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 reproducing head mounted on the rotating drum 29 at the time of recording and reproduction, and equalizes and demodulates the reproduction signal to obtain 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. As a result, the tape streamer 3 outputs data recorded on the magnetic tape 10 to the host computer 8 via the buffer memory 24, and data such as VIST can be obtained by the main CPU 23 as necessary. I have.

The ECC decoder 26 notifies the error detection result obtained in this way to the main CPU section 23 via the buffer memory 24, and thereby the main CPU
Under the control of the U unit 23, processing such as retry can be executed as needed. ECC decoder 2
6 simply executes an error detection process at the time of recording user data, records the resulting error detection result together with the user data and the like in the buffer memory 24,
This makes it possible to determine whether or not the data recorded in the read-after-write processing 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 predetermined processing procedure in response to a command input via the SCSI interface 21. The tape streamer 3 is mainly composed of a unit, controls the operation of the entire tape streamer 3, 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 unit 23 executed via 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 unit 23 via the DP-RAM 42, thereby the shelf 6A, the elevator 6
In B, information on the tape cassette can be obtained, and further, data communication with another computer system is possible.

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 / outputs data transmitted / received between the IC tags via the memory label interface 47 to / 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 10 is an Ethernet interface, and is connected to a predetermined network so that various information can be transmitted and received.

(1-2-1) Detailed Configuration of Tape Streamer FIG. 11 is a schematic diagram showing a part of a subcode set in each track set by the main CPU 23. In FIG. 11, for simplification of description, one bank is described as being allocated to an eight track set. Also, the track set in which the error has occurred is shown in a solid color.

The main CPU 23 sets a track identifier indicating the attribute of the track set to each track set. Here, the track identifier is a dummy ID (indicated by a symbol D) indicating a track set based on dummy data;
A user data ID (denoted by a symbol U) indicating a track set by user data, a tape mark ID (denoted by a symbol T) indicating a track set by a tape mark, and a data end ID (denoted by a symbol E) indicating a track set by an EOD. ).

The data necessary for the processing in the host computer 8 is shown in FIG.
As shown in the unnecessary section, the data of the track set by the user data and the data of the track set by the tape mark correspond to each other. Note that the track set by EOD is 4
This is valid when two consecutive tracks are set, and a tape mark or the like is subsequently recorded while leaving one of the four track sets. Therefore, the second file (FILE
The data end ID generated in the middle of 2) is generated when this track set is set to the temporary EOD and subsequently connected and recorded.

The main CPU section 23 controls the entire operation so that the tape mark is recorded on the magnetic tape 10 by three track sets, and dummy data is recorded for the first and last track sets. I do. Accordingly, the main CPU unit 23 controls the entire operation so that at least one track set records unnecessary data at a portion where data is recorded following the end of the data.

In the case of a meaningful track set in the host computer 8 as described above, the main CPU unit 23 increments the logical track set ID (logical ID) by a value of 1 for a track set having no meaning. Assigns the logical track set ID assigned to the immediately preceding track set as it is.

In this way, the main CPU unit 23 sets the subcode, records the track set,
The data fetched into the buffer memory 24 is processed by executing the processing procedure shown in FIG. 12 for each bank.

That is, the main CPU section 23 proceeds from step SP1 to step SP2, where it accesses the buffer memory 24 and determines an error flag to determine whether or not an error has occurred. If a negative result is obtained here, the main CPU unit 23 proceeds to step SP3.
To end the processing procedure. This allows the main C
The PU unit 23 switches the processing to the reproduction data of the following bank. Therefore, as shown by reference numeral (1) in FIG. 11A, when no error occurs in each bank, the main CPU section 23 selectively transmits the user data portion to the host computer 8.

On the other hand, if a positive result is obtained in step SP2, the main CPU unit 23 proceeds to step SP4. In this case, for the track set in which such an error has occurred, a logical track set ID,
Since the track identifier is also uncertain, the main CPU 23 determines the attribute of the track set in which the error has occurred. The main CPU 23 determines this attribute based on the continuity of the preceding and following logical track set IDs and the attribute of the adjacent track set.

That is, in this step SP4, the main CPU section 23 determines whether or not the increment of the front and rear track set IDs is due to a monotonic increase. In this case 1
When an error is detected alone in only one track set, it can be determined that the increase is due to a monotonic increase when the increment of the preceding and following track set IDs is 2. If an error is detected in two consecutive track sets,
If the increment of the track set IDs before and after is the value 3, it can be determined that the increase is due to monotonic increase. In this case, when the increment of the track set IDs before and after is monotonically increasing, as indicated by reference numeral (3) in FIG. 11, the error is detected by detecting the error in the continuous user track set. The detected track set is determined to be a track set in which data necessary for the host computer 8 is recorded. Accordingly, when a positive result is obtained in step SP4, the main CPU unit 23 proceeds to step SP5 from step SP4.
The track set in which the error has occurred is set as a necessary area, and the routine goes to step SP5.

On the other hand, if a negative result is obtained in step SP4, the main CPU unit 23 proceeds to step SP7. Here, in the case where the increment of the preceding and following track set IDs is not due to the monotonic increase, for example, when an error is detected alone in only one track set, the increment of the preceding and following track set IDs is a value. It becomes 1. In this case, in FIG. 11, the case where unnecessary data is allocated to the track set in which the error has occurred as shown by reference numeral (2), and the case where unnecessary data has been assigned to the track set in which the error has occurred as shown by reference numeral (4). There are two cases in which necessary data is allocated and unnecessary data is allocated to the subsequent track set.

Thus, in the following step SP7, the main CPU unit 23 determines the attribute of the track set in which the error has occurred based on the track set identifier of the track set after the adjacent track set. Specifically, it is determined whether or not the subsequent track set is an unnecessary track set, thereby determining the attribute of the track set in which an error has occurred. That is, the main CP
If a positive result is obtained in step SP7, the U unit 23 proceeds to step SP5, sets the track set where the error has occurred to a necessary area, and proceeds to step SP6.

On the other hand, if a negative result is obtained in step SP7, in this case, the track set in which the error has occurred can be determined to be a track set to which unnecessary data is allocated, and the process proceeds to step SP8.
Here, the main CPU unit 23 sets the track set in which the error has occurred to an unnecessary area, and proceeds to step SP6.

When the main CPU unit 23 determines the attribute of the track set in which the error has occurred in this way, in step SP6, it determines whether or not another error exists. It returns to step SP3. If there are no other errors,
The main CPU unit 23 proceeds from step SP6 to step S
Moving to P9, it is determined whether a retry is necessary.

Here, when the track set in which the error has occurred is set in the necessary area, the main CPU 23 determines that retry is necessary, proceeds to step SP10, instructs retry processing, and then proceeds to step SP3. Move on. On the other hand, if all track sets in which an error has occurred are set in the unnecessary area, the main CPU unit 2
No. 3 ignores the occurrence of an error in this case. That is, the main CPU unit 23 proceeds directly from step SP9 to step S9.
The process moves to P3, and this processing procedure ends.

Thus, when executing the retry process, the main CPU unit 23 rewinds the magnetic tape 10, reproduces the data recorded on the magnetic tape 10 for the corresponding bank, and repeats this processing procedure. Execute
Even if retry is repeated, an error status is sent to the host computer 8 and the process is stopped only when necessary data for this bank cannot be correctly reproduced.

(2) Operation of the First Embodiment In the above-described configuration, in the backup system 1 (FIGS. 1 and 2), the tape cassette stored in the shelf 6A is managed by the CPU unit 5 or 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 10). 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 a magnetic tape and plays back the VSIT, and the file designated by the host computer 8 can be accessed from the VSIT. The magnetic tape 10 is run. That is, when the first file is recorded on the magnetic tape 10, a predetermined interval from the VSIT
The IT is recorded, and subsequently the data output from the host computer 8 is sequentially recorded on the magnetic tape 10. Also, when appending to a previously recorded file, the DIT of the corresponding file is reproduced based on the VSIT recording, and this DIT
The end of the last block is detected from the IT, and data input from the host computer 8 is recorded sequentially from this end. When data reproduction is instructed from the host computer 8, the position of the corresponding file is set to VSIT.
Then, the DIT is accessed and the data recorded on the magnetic tape 10 is reproduced according to the recording of the DIT (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,
Under the management of the main CPU unit 23, a track identifier indicating the attribute of the track set is set for each track set, and the track identifier is used to set a track set using dummy data, a track set using user data,
Various data are recorded so that a track set by a tape mark and a track set by an EOD can be identified (FIG. 1).
1).

For a track set meaningful for processing in the host computer 8, a logical track set ID (logical ID) is sequentially incremented and recorded, and for a track set having no meaning,
The logical track set ID assigned to the immediately preceding track set is assigned and recorded as it is.

A tape mark is arranged between files, and the tape mark is set so that dummy data is recorded for the first and last track sets. At a portion where data is recorded subsequent to the end of the data, at least one track set is provided with a track set in which unnecessary data is recorded.

On the other hand, at the time of reproduction, a reproduction signal is obtained from a reproduction head mounted on the rotating drum 29, and the reproduction signal is processed by the equalizer circuit 30 to obtain reproduction data. The error correction processing is performed by the ECC decoder 26. Further, the data subjected to the error correction processing is recorded in the buffer memory 24 together with the error flag which is the result of the error correction processing.

In the tape streamer 3, the error flag recorded in the buffer memory 24 is accessed by the main CPU unit 23, and a retry process is executed for each bank only when an error occurs in necessary data.
Output of user data to the host computer 8 is stopped only when an error occurs in necessary data even after retry is repeated.

That is, in the tape streamer 3, the presence or absence of an error is determined by accessing the buffer memory 24. When the error is detected, the continuity of the logical track set ID before and after the track set in which the error occurred, and the error From the data recorded in the track set on the rear side among the track sets adjacent to the generated track set, it is determined whether the track set in which the error has occurred is a track set in which data necessary for processing by the host computer 8 is recorded. You.

That is, when the increment of the preceding and following logical track set IDs is monotonically increasing, the track set in which an error has occurred is determined to be a track set in which data necessary for processing by the host computer 8 has been recorded. If the increment of the preceding and following logical track set IDs is not due to a monotonic increase, the attribute of the following track set indicates
The attribute of the track set in which the error has occurred is determined, whereby it is determined whether the track set in which the error has occurred is a track set in which data necessary for processing by the host computer 8 is recorded. That is, in this case, the subsequent track set is a track set in which data unnecessary for processing by the host computer 8 such as a dummy track set is recorded, and if an error occurs in only one track set, an error occurs. Track set
It is determined that the track set records data necessary for the processing of the host computer 8.

Thus, when an error occurs in a track set in which data necessary for processing by the host computer 8 is not recorded, the tape streamer 3 can ignore the error and not execute the retry processing. Thus, a reduction in access speed due to useless retry is effectively avoided. Also, even when an error occurs in such a portion, the necessary reproduction data can be transmitted to the host computer 8, whereby the user data can be reliably transmitted to the host computer.

(3) Effects of the Embodiment According to the above configuration, when an error occurs, the continuity of the logical track set ID before and after the track set in which the error is detected and the track in which the error is detected By ignoring the occurrence of an error by the determination based on the track identifier set in the track set adjacent to the set, even if an error occurs in the reproduced data, the user data is reliably transmitted to the host computer as the host device. be able to.

(4) Second Embodiment By the way, when the track pitch is dense, the accuracy of writing with respect to the track width is relatively reduced. For this reason, when joint writing is performed, the track width of some tracks of the previous track set becomes narrower at the jointed portion due to overwriting, and there is a possibility that data cannot be correctly reproduced for this track set. Further, if the track pitch changes at the linked portion, the tracking is temporarily disturbed, and as a result, data may not be correctly reproduced for the linked track set at the head.

Thus, in this embodiment, even in such a case, the user data can be reproduced correctly, and in combination with the determination of the attribute of the track set in which the error has occurred as described in the first embodiment, the user data can be reproduced. Ensure that data can be sent to the host computer.

In this connection, the data transfer speed of the user data sent from the host computer 8 is lower than the data transfer speed in the recording system of the tape streamer 3.
This is the case where the running stop is repeated.

In this embodiment, the main CPU
This embodiment has the same configuration as that of the first embodiment except that the process of setting a track set by the unit 23 is different from that of the above-described first embodiment. Only the following will be described, and redundant description will be omitted.

In this embodiment, when the running of the magnetic tape 10 is stopped, the main CPU unit sets the last four track sets to the EOD track set, so that at least the last track set is set. And assign unnecessary data. That is, as shown in the first and third times in FIG.
Or, when the file 3 is recorded and the running of the magnetic tape 10 is stopped, or when the tape mark is recorded and the running of the magnetic tape 10 is stopped as shown in FIG.
The last four track sets are set as EOD track sets. For the EOD track set,
Being effective by the 4-track set, the main CPU unit takes the above into account and takes into account the buffer memory 2.
Four banks will be managed.

Also, with regard to the tape mark, data may be additionally written by adding a block,
By setting the first and last track sets of the three track sets as dummy track sets, unnecessary data is allocated to these first and last track sets.

On the other hand, in the case of joint writing, the main C
The PU unit leaves at least one track set to which unnecessary data is allocated in a part before the boundary to be connected.

In other words, when connecting and writing from the track set portion of the EOD, the main CPU makes the track set of the EOD invalid by setting the physical track set ID issued to the servo system.
For at least one of the OD track sets, a subsequent track set is recorded so as to keep the recording. More specifically, in FIG. 13, the main CPU unit shown in FIG. 13 shows a tape image from the first recording to the second recording, so that only the first track set of the EOD of the four track sets is left, Record the set. In FIG. 13, joints are indicated by arrows.

When data is additionally recorded with the tape mark portion invalidated, the main CPU section invalidates the tape mark and records at least one of the track sets of the tape mark. Record the next set of tracks so that they remain. Specifically, in FIG.
The next track set is recorded so that only the first track set of the tape mark of the three track sets is left so as to show the tape image of the third recording from the first recording.

On the other hand, when updating a file, the immediately preceding tape mark is kept valid and the subsequent track set is recorded. Specifically, the main CPU unit is configured as shown in FIG.
In 3, a track set following the last track set of the tape mark of the three track sets is recorded so as to show the tape images of the third to fourth recordings.

[0108] In the case of the joint writing as described above, the unnecessary data is allocated to the head track set at the start of the joint writing by setting the dummy track set.

Thus, in the case of connecting and writing from the EOD portion as in the first and second times in FIG.
The main CPU allocates a track set in which unnecessary data, which is one of the track sets based on EOD, to be recorded, and a dummy track set assigned before the tape mark track set before and after the joint. Similarly, as in the second to third times, when additional recording is performed on file 2, a track set recording unnecessary data, which is the first track set of the tape mark track set, and a first track set of the file to be additionally recorded Are assigned to the front and back of the joint. Similarly, when the file 3 is rewritten as in the third to fourth times, the track set in which the last unnecessary data is recorded by the tape mark arranged before the file 3 and the first track set in the file 3 Unnecessary data is recorded and assigned to the track set before and after the joint.

Thus, the main CPU selectively assigns a track set with unnecessary data before and after the joint, which is a part where errors frequently occur. The main CPU sets the track identifier and the logical track set ID so as to correspond to the setting of the track set by such unnecessary data.

At the time of reproduction, the main CPU unit determines an error by determining the continuity of the preceding and following logical track set IDs and the attribute of the adjacent track set, as in the main CPU unit 23 described in the first embodiment. Ignore the occurrence of. Thus, the main CPU reliably sends the user data to the host computer even when an error occurs.

That is, as shown in FIG. 14, the image at the time of reproduction after the fourth recording in FIG. 13 is compared with FIG. 11, as shown in FIG. The user data stored in the memory 24 can be selectively output to the host computer 8 to supply data necessary for processing of the host computer 8.

If an error occurs in a track set which is not before or after the boundary where the joint recording has been performed, the relationship between the track identifier and the logical track set ID is set to the same as described above with reference to FIG. Thus, also in this case, the user data stored in the buffer memory 24 can be selectively output to the host computer 8 to supply data necessary for processing of the host computer 8.

On the other hand, even in the case of a linked portion, the attribute of the track set in which an error has occurred is determined by determining the continuity of the preceding and following logical track set IDs and the attribute of the adjacent track set. An error can be handled in the same manner as in the first embodiment.

In this embodiment, the main CP
The U unit determines the attribute of the track set in which the error has occurred from the attribute of the subsequent track set with reference to the increment of the preceding and following logical track set IDs. That is, in the arrangement of the track sets as in the first embodiment, a track set in which necessary data is recorded is always arranged before and after a track set in which unnecessary data is recorded, except for an EOD track set. Will be. On the other hand, in this embodiment, a track set in which unnecessary data is exceptionally continuous continues before and after the boundary where the joint recording is performed.

Thus, for example, as shown by reference numeral (2) in FIG. 14, when an error is detected in only one track set, the increment before and after is a value of 1 and is necessary for a subsequent track set. When data is allocated, the attribute of the track set in which the error has occurred can be determined to obtain a correct determination result, as in the case where an error has occurred in a portion different from the vicinity where the joint recording has been performed. .

On the other hand, as shown by reference numerals (3) and (4) in FIG. 14, when an error occurs in one track set before and after the boundary, the increment of the logical track set ID becomes 0. May occur. However, in this case, since the increment is a value of 0, it can be determined that unnecessary data is continuously allocated to three track sets including the preceding and following track sets. In such a case, the attribute of the track set in which the error is detected is determined to be a track set in which unnecessary data is recorded.

Also in the vicinity of such a jointly recorded portion, as shown by reference numeral (5) in FIG. 14, when an error is detected in only one track set, the increase before and after the value is 1 If the unnecessary data is assigned to the subsequent track set,
As in the case where an error has occurred in a portion different from the vicinity where the joint recording has been performed, the attribute of the track set in which the error has occurred can be determined as a track set in which necessary data is recorded, and a correct determination result can be obtained. .

On the other hand, in FIG.
As shown by (8), in a portion adjacent to the boundary, although extremely rare, an error may be detected in two consecutive track sets. Also in this case, as described above, the main CPU determines the attribute of the track set in which the error has occurred from the continuity of the preceding and following logical track set IDs and the attribute of the adjacent track set in the same manner as described above. Can be.

That is, when an error occurs in two consecutive track sets, the logical track set I / O
If the increment of D is a value of 1 and necessary data is allocated to a subsequent track set, or if the increment of a preceding and following logical track set ID is a value of 0, these two track sets have It is possible to determine a track set to which necessary data is allocated.

When an error occurs in two track sets, the increment is a value of 2, and when necessary data is allocated to a subsequent track set, these 2
In one track set, it can be determined that a track set to which unnecessary data is assigned and a track set to which necessary data are assigned.

Thus, in this embodiment,
After determining the attribute of the track set in which the error occurred,
The same processing as that of the first embodiment is executed based on the determination result.

By allocating unnecessary data to the track sets before and after the joint as in the second embodiment, it is possible to record user data while avoiding portions where errors frequently occur. Thus, even when an error occurs in the reproduced data in a portion where such an error frequently occurs, the user data can be reliably transmitted to the host computer.

At this time, it is possible to further reliably transmit user data to the host computer by ignoring the occurrence of an error by judging the continuity of the logical track set ID and the data recorded in the adjacent track set. it can.

(5) Third Embodiment In the case of reproducing from the middle of a magnetic tape, the attribute of a track set in which an error has occurred may not be determined by the above-described method. For this reason, in this embodiment, a bridging flag indicating recording by bridging is set. Note that in this embodiment, a series of processes relating to the setting of the linking flag is performed by the first process described above.
This embodiment is the same as the configuration according to the first embodiment except for the points different from the first embodiment. Therefore, in this embodiment, only this different configuration will be described, and redundant description will be omitted.

That is, as shown in FIG. 15, in the case of joint recording, as shown in FIG. 15, the main CPU unit sets a joint writing flag indicating the joint recording at a predetermined position behind the boundary of the joint recording. Here, the main CPU unit is involved in the processing of the same bank as the track set from which the link recording is started, and assigns the user data necessary for the processing of the host computer to the track set closest to the boundary of the link. Set the join flag. Specifically, a bridging flag is set in the second track set after the bridging boundary.

In this joint recording, similarly to the above-described second embodiment, a track set is set so that unnecessary data is assigned to the track sets before and after the joint.

On the other hand, at the time of reproduction, the main CPU
The occurrence of an error is ignored only for the part which is connected by the processing based on the connection flag. In other words, after various examinations, the fact that the user data cannot be transferred to the host computer due to the occurrence of an error is due to an error in the concatenated portion. It has been found that practically sufficient characteristics can be secured without determining the attribute of the track set.

Accordingly, in this embodiment, the main CPU processes the error detection result by executing the processing procedure shown in FIG. That is, the main CPU unit proceeds from step SP11 to step SP12, where the main CPU unit accesses the buffer memory 24 and determines an error flag to determine whether an error has occurred. Here, if a negative result is obtained, the main CPU proceeds to step SP13 and ends this processing procedure.

On the other hand, in step SP12,
If a positive result is obtained, the main CPU unit proceeds to step S
Move to P14. Here, the main CPU determines whether or not a linking flag is set at a predetermined position for the track set in which the error has occurred. At this point, the CPU unit determines whether the track set where the error has occurred is 1 or 2
If the tying flag is set after the track is set, it is determined that the tying flag is set at a predetermined position. If the writing flag is not set, it is determined that the link writing flag is not set at a predetermined position.

If a negative result is obtained here, the main CP
The U section moves to step SP15, sets this error occurrence location in a necessary area, and then moves to step SP16.
On the other hand, if a positive result is obtained in step SP14, the main CPU unit shifts to step SP17. Here, this error occurrence is set in an unnecessary area, and step SP1
Move to 6.

The main CPU unit determines in step SP16
In, it is determined whether or not there is another error. If an affirmative result is obtained, the process returns to step SP13. On the other hand, if no other error has occurred, the main CP
The unit U moves from step SP16 to step SP18, and determines whether a retry is necessary.

Here, when the track set in which the error has occurred is set in the necessary area, the main CPU determines that retry is necessary, and proceeds to step SP19. After instructing retry processing, the main CPU proceeds to step SP13. . On the other hand, when all the track sets in which an error has occurred are set in the unnecessary area, the main CPU ignores the occurrence of the error in this case. That is, the main CPU directly proceeds from step SP18 to step SP13, and ends this processing procedure.

As a result, the main CPU unit operates as shown in FIG.
As shown in (1), when an error occurs in one track set after the joint during reproduction from the joint, the error can be ignored by setting the subsequent joint writing flag. On the other hand, as shown in FIG. 15 (2), when an error occurs in the two track set after the seam in the reproduction from the same seam, in this case, the connection writing flag cannot be detected. The track set on which the data is recorded can be processed without ignoring errors.

On the other hand, as shown in FIG.
In the reproduction after one track set from the joint, FIG.
When an error occurs in the track set as in the case of (1), in this case, the error cannot be detected by the reproduced data itself, and there is no problem. On the other hand, as shown in FIG. 15 (4), when an error occurs in the track set as in the case of FIG. 15 (2) in the reproduction after one track set from the joint, the joint writing flag is set. Since the data cannot be detected, it is possible to perform processing without ignoring errors in a track set in which necessary data is recorded.

Also, as shown in FIG. 15 (5), when an error occurs in two track sets across a joint when reproducing from one track set before the joint, these two flags are set by the joint writing flag. Track sets can be processed ignoring errors. On the other hand, as shown in FIG. 15 (6), in the case where reproduction is performed from one track before the joint, 2
When an error occurs in one track set and the following one track set, since the linking flag cannot be detected, it is possible to perform processing without ignoring errors in the track set in which necessary data is recorded.

Further, as shown in FIG. 15 (7), when an error occurs in two track sets across the joint when reproducing from two sets before the joint, these two flags are set by the joint writing flag. Track sets can be processed ignoring errors. On the other hand, as shown in FIG. 15 (8), when an error occurs in two track sets straddling a seam and one track set before these in a reproduction from the same track set, a joint writing is performed. Since the flag cannot be detected, it is possible to perform processing without ignoring errors in a track set in which necessary data is recorded. FIG.
As shown in (9), in the case where an error occurs in two track sets straddling a seam and a track set before and after these in a reproduction from a similar track set, a link writing flag cannot be detected in this case as well. Accordingly, it is possible to perform processing without ignoring errors in a track set in which necessary data is recorded.

As a result, when reproducing from the middle of the magnetic tape, even if an error occurs in the reproduced data, the user data can be reliably transmitted to the host computer.

According to the third embodiment, a track set in which unnecessary data is recorded is arranged before and after a concatenated boundary, and further, a track set at a predetermined position after the concatenated boundary is added to the track set. By setting a bridging flag indicating a crossed boundary, even if an error occurs in reproduced data, user data can be reliably transmitted to the host computer.

(6) Other Embodiments In the above-described first and second embodiments, the attribute of the track set on the rear side among the track sets adjacent to the track set in which an error has occurred is used as a reference. However, the present invention is not limited to this, and the data recorded in this track set, which is the attribute of the preceding track set among the track sets adjacent to the track set in which the error occurred, is described. May be disregarded on the basis of the above, or the track set of such a criterion may be appropriately switched and processed according to an error occurrence location in one bank.

In the third embodiment described above,
Although the case where the joint flag is set after setting two tracks of the joint has been described, the present invention is not limited to this, and the point is that the joint flag may be set so as to have a certain relationship with the joint. It can be set in various places as needed.

In the third embodiment described above,
The case where only one type of identifier is set by the bridging flag has been described. However, the present invention is not limited to this. Alternatively, in this case, for example, a count value that is sequentially incremented in track set units from the joint may be used as the identifier.

In the third embodiment described above,
Although the case where the error is simply ignored based on the connection flag has been described, the present invention is not limited to this, and the determination method according to the first embodiment may be applied together.

Further, in the above-described embodiment, a case has been described where one track set is constituted by four tracks and errors are determined in units of this track set. However, the present invention is not limited to this, and a plurality of tracks other than four tracks are used. The present invention can be widely applied to a case where one track set is composed of tracks and an error is determined in units of this track set, and furthermore, an error is determined and processed in units of tracks.

In the above-described embodiment, the case where the present invention is applied to the tape streamer in combination with the transport mechanism has been described. However, 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 computer data 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. .

[0147]

As described above, according to the present invention, the continuity of the first identifiers assigned to the recording tracks before and after the recording track in which the error is detected, and the attribute of the adjacent recording track is determined. By ignoring errors,
Also, before and after the concatenated boundary, a recording track on which unnecessary data is recorded is formed, and further, by ignoring the error based on the presence or absence of the concatenated identifier for the recording track where the error is detected, the reproduction is performed. Even if an error occurs in the input data, the user data can be reliably transmitted to the host device.

[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 block diagram showing the tape streamer of FIG. 3;

FIG. 11 is a schematic diagram for explaining an error process in the tape streamer of FIG. 3;

FIG. 12 is a flowchart showing a processing procedure of FIG. 11;

FIG. 13 is a schematic diagram for explaining setting of a track set in a tape streamer according to a second embodiment of the present invention.

FIG. 14 is a schematic diagram for explaining an error process in the tape streamer of FIG. 13;

FIG. 15 is a schematic diagram for explaining error processing in a tape streamer according to a third embodiment of the present invention.

FIG. 16 is a flowchart showing the procedure of the process in FIG. 15;

[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 unit, 24 ... Backup memory, 25 ... E
CC encoder, 26 ECC decoder

Continued on front page F term (reference) 5D044 AB01 BC01 CC03 DE12 DE38 DE49 DE64 DE69 DE83 EF05 FG18 5D110 AA04 BB16 CA04 CA10 CA13 CB01 CC03 CK24 CK26

Claims (7)

[Claims] 1. A method of reproducing data recorded on a magnetic tape in units of a plurality of recording tracks, detecting an error in the reproduced data, and outputting the reproduced data to an external device based on a detection result of the error. In the data processing device, the recording track includes: a first identifier set so that a value changes by a predetermined value only for a recording track on which necessary data is recorded;
A second identifier indicating the attribute of the recorded data is recorded. Unnecessary data is recorded on the leading and trailing recording tracks of the plurality of recording tracks of the tape mark, and / or following the end of the data. Unnecessary data is recorded on at least one recording track in a portion where data has been recorded by using the first identifier assigned to recording tracks before and after the recording track where the error was detected. Processing the reproduced data ignoring the error detection by the determination based on the continuity of the error and the second identifier set on the recording track adjacent to the recording track on which the error is detected. Data processing device. 2. A data processing apparatus for recording desired data on a magnetic tape in units of a plurality of recording tracks, wherein a recording track on which unnecessary data is recorded is arranged before and after a boundary of the joint writing. Characteristic data processing device. 3. The data processing apparatus according to claim 1, wherein an identifier indicating the boundary of the joint is set in a predetermined recording track near the boundary of the joint. 4. A method for reproducing data recorded on a magnetic tape in units of a plurality of recording tracks, detecting an error in the reproduced data, and outputting the reproduced data to an external device based on a result of the detection of the error. In the data processing device, the magnetic tape has recording tracks on which unnecessary data is recorded before and after the boundary of the joining, and the recording track of the joining is provided on a predetermined recording track near the boundary of the joining. A bridging identifier indicating a boundary is set, and the data processing device processes the reproduced data ignoring the error detection depending on the presence or absence of the bridging identifier for the recording track where the error is detected. A data processing device characterized by the above-mentioned. 5. A method for reproducing data recorded on a magnetic tape in units of a plurality of recording tracks, detecting an error in the reproduced data, and outputting the reproduced data to an external device based on the error detection result. In the method of reproducing data, the recording track comprises: a first identifier set so that a value changes by a predetermined value only for a track on which necessary data is recorded; and a second identifier indicating an attribute of the recorded data. Is recorded, unnecessary data is recorded on the first and last recording tracks of the plurality of recording tracks of the tape mark, and / or at least one part is recorded on a portion where data is recorded following the end of the data. Unnecessary data is recorded on one recording track, and the method of reproducing the data is assigned to recording tracks before and after the recording track where the error is detected. By determining the continuity of the first identifier obtained and the second identifier set on a recording track adjacent to the recording track on which the error is detected, the reproduction data is ignored ignoring the error detection. A method for reproducing data characterized by processing. 6. A data recording method for recording desired data on a magnetic tape in units of a plurality of recording tracks, wherein a recording track on which unnecessary data is recorded is arranged before and after a boundary of the joint writing. A method for recording data, characterized in that: 7. A method of reproducing data recorded on a magnetic tape in units of a plurality of recording tracks, detecting an error in the reproduced data, and outputting the reproduced data to an external device based on a result of the detection of the error. In the method of reproducing data, the magnetic tape has recording tracks on which unnecessary data is recorded before and after the boundary of the linking, and the recording track on the predetermined recording track near the boundary of the linking. The data reproducing method is configured to process the reproduced data ignoring the error detection depending on the presence or absence of the bridging identifier for the recording track where the error is detected. A method for reproducing data.