JPH11242802A - System and method for managing deteriorating area of magnetic tape and record medium stored with magnetic tape device control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to use the area on a magnetic tape except its deteriorating area. SOLUTION: The magnetic tape 13 is constituted as a collection of partitions, which each consists of a management information block and data blocks following it. A magnetic tape device control part 11 records data blocks following the management information block of a following partition by skipping a partition where information showing that partition access is disabled is recorded at the management information block at the head of the partition, and reproduces data from the data block following the management information block of a following partition by skipping the partition where information showing that partition access is disabled is recorded at the management information block at the head of the partition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a technique for managing a deteriorated area of a magnetic tape, and more particularly, to a method and a method for managing a deteriorated area in units of partitions of a magnetic tape.

[0002]

2. Description of the Related Art Conventionally, in a magnetic tape device used for recording and reproducing data handled by a host computer, when a deteriorated area exists on a magnetic tape, for example, Japanese Patent Application Laid-Open No. 57-200917 is disclosed. As described in detail in US Pat. No. 6,064,897, the use of an area that is still available other than that area increases the life of the magnetic tape.

In the method disclosed in the above publication, a data block is composed of a flag portion indicating the validity of the immediately preceding data block and a data portion, and a data block in which an error has occurred during recording has a flag indicating the error in the data. After the addition, recording is performed again. If no error occurs during recording, a flag indicating that there is no error is added to the data to be recorded next to form the next data block, and this is recorded.

[0004]

In the above-described conventional method for managing a deteriorated area of a magnetic tape, the data block is composed of a flag portion indicating the validity of the immediately preceding data block and the data portion, so that an error during recording can be prevented. Change the flag part of the resulting data block to a flag indicating an error,
There has been a problem that the contents of the flag indicating the validity of the data block immediately before the data block in which the error has occurred are lost.

Further, the validity of the reproduced data block is determined based on the content of the flag of the next reproduced data block. To determine the validity of the next reproduced data block, the validity of the next data block is further determined. Must be reproduced, and this operation continues for a long time. Therefore, there is a problem that the validity of the last data block having no next data block cannot be determined.

Further, since the validity of the reproduced data block is checked for each data block, there is a problem that performance at the time of reproduction is deteriorated.

[0007]

According to a first aspect of the present invention, in a magnetic tape deterioration area management method, even if a deteriorated area exists on the magnetic tape, access to the deteriorated area is avoided. A magnetic tape device control unit that allows access to only an area other than the deteriorated area is provided.

In a second aspect of the present invention, in the first aspect, the area is managed on a partition basis.

A third invention of the present application is the magnetic tape deterioration area management system, wherein the magnetic tape is configured as a set of a plurality of partitions, and the partitions are composed of a management information block followed by a plurality of data blocks; When recording the data received from the host computer on the magnetic tape, if information indicating that the partition is not accessible is recorded in the management information block at the head of the partition, the partition is skipped and the subsequent partition is not accessible. Information is recorded in the data block following the management information block of the partition in which the information is not recorded in the management information block, and the data is reproduced from the magnetic tape in order to transmit the data to the host computer. In this case, if the information that the partition is inaccessible is recorded in the management information block at the beginning of the partition, the partition is skipped, and the information that the subsequent partition is inaccessible is not recorded in the management information block. A magnetic tape device control unit for reproducing data from the data block following the management information block of the partition is provided.

[0010] In a fourth aspect of the present invention based on the third aspect, the magnetic tape device control section accesses the management information block of the partition when the data cannot be recorded in the data block of the partition. The information that the data cannot be recorded is recorded, and the data recorded in the data block before the data block in which the data could not be recorded is re-recorded in the subsequent partition.

According to a fifth aspect of the present invention, in the magnetic tape deterioration area management method, the magnetic tape is configured as a set of a plurality of partitions, and each of the partitions includes a management information block followed by a plurality of data blocks. When data received from a host computer is recorded on the magnetic tape, if information indicating that partition access is impossible is recorded in the management information block at the beginning of the partition, the partition is skipped and the subsequent partition access is performed. The data is recorded in the data block following the management information block of the partition in which the information indicating that the information is not recorded in the management information block, and the data is reproduced from the magnetic tape in order to transmit the data to the host computer. In this case, if the information that the partition is inaccessible is recorded in the management information block at the head of the partition, the partition is skipped, and the information that the subsequent partition is inaccessible is recorded in the management information block. Data is reproduced from the data block following the management information block of the non-partition.

According to a sixth aspect of the present invention, in the fifth aspect, when data cannot be recorded in the data block of the partition, the information that the partition cannot be accessed is recorded in the management information block of the partition. The data recorded in the data block up to the data block before the data could not be recorded is re-recorded in the subsequent partition.

According to a seventh aspect of the present invention, the data received from the host computer is transmitted to the magnetic tape composed of a management information block and a plurality of data blocks following the management information block. When recording on a magnetic tape, if the information indicating that the partition is inaccessible is recorded in the management information block at the beginning of the partition, the partition is skipped and the information that the subsequent partition is inaccessible is recorded in the management information block. Recording data in the data block following the management information block of the partition that has not been
When reproducing data from the magnetic tape, if the information indicating that the partition is inaccessible is recorded in the management information block at the beginning of the partition, the partition is skipped, and the subsequent information that the partition is inaccessible is indicated by the management. When data is reproduced from the data block following the management information block of the partition not recorded in the information block, and data cannot be recorded in the data block of the partition, the partition access to the management information block of the partition is performed. A magnetic tape device control program for rewriting data recorded in a data block up to the data block before the data block in which the information indicating that the data block was not recorded and in which the data could not be recorded in a subsequent partition Characterized in that it is a recording medium storing.

[0014]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention.

Referring to FIG. 1, an embodiment of the present invention comprises:
In the magnetic tape device 1, the magnetic tape device control unit 11
And a recording / reproducing head 12 and a magnetic tape 13.

A magnetic tape device control unit 11 records data received from a host computer on a magnetic tape, and transmits data reproduced from the magnetic tape to the host computer. And a partition management unit 111 that manages the partitions that make up.

FIG. 2 is a configuration diagram of a partition showing an embodiment of the present invention.

The magnetic tape 21 is configured as a set of a plurality of partitions, and the partition 22 includes a management information block 23 and a plurality of data blocks 24 following the management information block 23.
Consists of

The management information block 23 is an area for managing information on the partition to which it belongs. The data block 24 is an area for recording and reproducing data handled by the host computer.

Next, the operation of the embodiment of the present invention will be described in detail with reference to FIGS. FIG. 3 is an operation explanatory diagram showing an embodiment of the present invention.

The magnetic tape device controller 11 attempts to record the data received from the host computer on the magnetic tape 13.

At this time, if the recording / reproducing head 12 is positioned 34 just before the data block, the data is recorded in the data block.

The recording / reproducing head is immediately before the partition (between partitions, 35 in FIG. 3).
Is located, the partition management unit 111 of the magnetic tape device control unit 11 reads the partition management information block 31 at the head of the partition in order to determine whether the partition can be accessed. If information indicating that partition access is not allowed is recorded in the management information block 31, data is not recorded in that partition (for example, partition n in FIG. 3), and data is recorded in the succeeding accessible partition n + 1. Skip partition n which is inaccessible. If the information that the partition cannot be accessed is not recorded in the management information block, the data is recorded in the data block 32 following the management information block.

If data could not be recorded in the data block due to the deterioration of the tape medium, the partition management means 111 of the magnetic tape device control section sends management information of the partition to which the deteriorated area (for example, 33 in FIG. 3) belongs. Information indicating that partition access is not allowed is recorded in block 31. Then, in the same partition (partition n), the data recorded in the data block up to before the degraded area is re-recorded in the succeeding accessible partition (partition n + 1). After that, the data to be recorded first is recorded.

As a method of detecting a degraded area on a magnetic tape, the recorded data is reproduced by a reproducing head almost at the same time as the data is recorded by a recording head to determine whether the data is error-free. There is a technique called “Read after Write” that checks for the following.

The magnetic tape device control section 11 controls the magnetic tape 1 to transmit data to the host computer.
Try to play data from 3

At this time, if the recording / reproducing head 12 is positioned 34 just before the data block, the data is reproduced from the data block.

The recording / reproducing head is positioned immediately before the partition (between partitions, for example, as shown in FIG. 3).
(35), the partition management unit 111 of the magnetic tape device control unit reads the partition management information block 31 at the head of the partition to determine whether the partition can be accessed. Read. If the information indicating that the partition is inaccessible is recorded in the management information block, the data is not reproduced from the partition (partition n), and the inaccessible partition is reproduced to reproduce the data from the succeeding accessible partition (partition n + 1). (Partition n) is skipped. If the information indicating that partition access is not allowed is not recorded in the management information block, data is reproduced from the data block 32 following the management information block.

Next, FIG. 4 is a block diagram showing a second embodiment of the present invention, and FIG. 5 is a diagram showing a configuration example of a partition management table in FIG.

Referring to FIG. 4, in the second embodiment of the present invention, a nonvolatile memory 45 is built in a cartridge 44 in which a magnetic tape 43 is stored. The partition is composed of only a plurality of data blocks, and the partition management information is held in the nonvolatile memory 45.
Partition management information is stored in the non-volatile memory 45.
The partition is managed by a partition management table 51 which is a set of entries 52 holding information on whether or not each partition is accessible.

The partition management means 411 of the magnetic tape device controller 11 determines whether or not the partition can be accessed.
Reference is made to the information held in the entry 52 corresponding to the partition in the partition management table 51 in 5. Also, “Read after Wr
If the data could not be recorded in the data block due to the deterioration of the tape medium detected by "item", the entry 52 corresponding to the partition to which the deteriorated area belongs in the partition management table 51 in the nonvolatile memory 45. And information that the partition cannot be accessed.

According to this method, the partition management information is managed by a non-volatile memory built in the cartridge in which the magnetic tape is stored, so that the partition management information is stored on the magnetic tape as in the first embodiment. In this case, the problem that the partition management information block area itself becomes inaccessible due to deterioration of the tape medium or the like is solved.

Next, a third embodiment of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 6, the third embodiment of the present invention includes a recording medium 60 storing a magnetic tape device control program. The recording medium 60 may be a magnetic disk, a semiconductor memory, or another recording medium.

The magnetic tape device control program is read from the recording medium 60 into the data processing device 61 and controls the operation of the data processing device 61. The data processing device 61 executes the same processing as the magnetic tape device control unit on the magnetic tape in the first embodiment under the control of the magnetic tape device control program.

[0037]

As described above, according to the present invention, the area to be recorded / reproduced can be accessed before the data is recorded on the magnetic tape or before the data is reproduced from the magnetic tape. Means for skipping the inaccessible area if access is not possible, so that even if there is a degraded area on the magnetic tape, access to only the degraded area is avoided. However, there is an effect that a normal usable area can be used reliably and stably.

Further, according to the present invention, the magnetic tape is constituted as a set of a plurality of partitions, and it is possible to check whether an area to be recorded / reproduced is accessible in units of partitions. The number of times of inspection is smaller than that of the above-mentioned inspection, and the performance at the time of reproduction is improved as compared with the conventional method.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a partition according to the first embodiment of the present invention.

FIG. 3 is an operation explanatory diagram showing the first embodiment of the present invention.

FIG. 4 is a block diagram showing a second embodiment of the present invention.

FIG. 5 is a diagram showing a configuration example of a partition management table in FIG. 4;

FIG. 6 is a block diagram showing a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic tape apparatus 11 Magnetic tape apparatus control part 111,411 Partition management means 12 Recording / reproducing head 13,43 Magnetic tape 21 Magnetic tape 22 Partition 23,31 Management information block 24,32 Data block 33 Deterioration area 44 Cartridge 45 Non-volatile memory 51 partition management table 52 entry 60 recording medium 61 data processing device

Claims (7)

[Claims] In a magnetic tape deterioration area management method, even if a deteriorated area exists on the magnetic tape, access to the deteriorated area is avoided, and access can be made only to an area other than the deteriorated area. A magnetic tape deterioration area management method, comprising: a magnetic tape device control unit. 2. The method according to claim 1, wherein the area is managed on a partition basis. 3. A magnetic tape deterioration area management method, wherein the magnetic tape is configured as a set of a plurality of partitions, the partitions including a management information block and a plurality of subsequent data blocks, and data received from a host computer. Is recorded on the magnetic tape, if the information that the partition is inaccessible is recorded in the management information block at the head of the partition, the partition is skipped and the information that the subsequent partition is inaccessible is the management information. When data is recorded in the data block following the management information block of the partition not recorded in the block and data is reproduced from the magnetic tape to transmit the data to the host computer, the partition is If the information indicating that the partition is inaccessible is recorded in the management information block at the beginning of the partition, the partition is skipped and the subsequent information that the partition is inaccessible is not recorded in the management information block. A method for managing a deteriorated area of a magnetic tape, comprising a magnetic tape device control unit for reproducing data from the data block following an information block. 4. When the data cannot be recorded in the data block of the partition, the magnetic tape device control unit records the information that the partition cannot be accessed in the management information block of the partition, and can record the data. 4. The method according to claim 3, wherein the data recorded in the data block preceding the data block which has not been recorded is re-recorded in a subsequent partition. 5. A method for managing a deteriorated area of a magnetic tape, comprising: a set of a plurality of partitions, wherein the partitions include the magnetic tape including a management information block and a plurality of data blocks following the management information block, and received from a host computer. When the data is recorded on the magnetic tape, if information indicating that the partition is inaccessible is recorded in the management information block at the beginning of the partition, the partition is skipped and the information that the subsequent partition is inaccessible is indicated by the management. When data is recorded in the data block following the management information block of the partition not recorded in the information block and the data is reproduced from the magnetic tape in order to transmit the data to the host computer, If the information indicating that the partition is inaccessible is recorded in the management information block at the beginning of the partition, the partition is skipped, and the subsequent management of the partition in which the information that the partition is inaccessible is not recorded in the management information block is performed. A method for managing a deteriorated area of a magnetic tape, comprising reproducing data from the data block following an information block. 6. When data cannot be recorded in the data block of the partition, the information that the partition cannot be accessed is recorded in the management information block of the partition, and the data is not recorded before the data block in which the data could not be recorded. 6. The method according to claim 5, wherein the data recorded in the data block is re-recorded in a subsequent partition. 7. A method for recording data received from a host computer on a magnetic tape comprising a management information block and a plurality of data blocks following the management information block, wherein the partition is configured as a set of a plurality of partitions. If the information indicating that the partition is inaccessible is recorded in the management information block at the beginning of the partition, the partition is skipped, and the subsequent information of the partition that is inaccessible is not recorded in the management information block. When data is recorded in the data block following the information block and the data is reproduced from the magnetic tape, the information that the partition cannot be accessed is recorded in the management information block at the head of the partition. If the partition has been skipped, the data is reproduced from the data block following the management information block of the partition in which the information that the subsequent partition is inaccessible is not recorded in the management information block, and the data of the partition is read. When data cannot be recorded in a block, the information that the partition is inaccessible is recorded in the management information block of the partition, and the data recorded in the data block up to the data block before the data block in which the data could not be recorded is a subsequent partition. A recording medium storing a magnetic tape device control program to be re-recorded with respect to.