JPH09128156A - Recording control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always maintain the validity of data in a disk even when a fault is generated before writing processing in the disk after a write end report by write after control. SOLUTION: The system has a data recording/reproducing device for recording/reproducing data in/from a magnetic disk with a fixed length format and a data format converter 13 for converting the format of data by a conversion table stored in a cache memory in accordance with a recording/reproducing instruction outputted from a host computer supposing a magnetic disk with a variable length format. In this case, a conversion table saving area for temporarily saving the contents of the conversion table is prepared in each data recording/reproducing device. When the rewriting processing of data updated in the conversion table in accordance with a recording/reproducing instruction to the data recording/reproducing device is not normally executed, the contents of the conversion table are saved to a conversion table saving area prepared in another normal data recording/reproducing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording control system, and more particularly, to an actual writing process of data on a disc when the data of the variable length format is format-converted and recorded on a fixed length format disc device. Relates to a recording control system which is performed after a writing completion report to the host computer.

[0002]

2. Description of the Related Art Conventionally, in the field of magnetic disk devices, when recording variable-length record data having different sizes on a recording / reproducing disk, the variable-length format magnetic disk can record the record data as it is. It was common to use a device. However, in recent years, SCSI (Small Computer System Interface)
A general-purpose interface capable of realizing a smaller and lower-priced magnetic disk device such as is often used. For this reason, it is becoming more common to use a fixed-length format magnetic disk device that inevitably records and reproduces fixed-length block data.

FIG. 7 is a diagram for conceptually explaining the structure of the variable length format. In the figure, a plurality of records having different sizes are continuously provided on the disc. Each record is composed of a fixed-length record information part and a variable-length data part. The record information section holds a record ID unique to the record and a data length indicating the size of the data section immediately following the record information section. The data section holds specific record data having the above data length. When reading and writing record data with this variable length format magnetic disk device, first, a record information section having a designated record ID is searched. Then, if the corresponding record information section exists, the record data is continuously read and written for the data section immediately following the record information section.

FIG. 8 is a diagram for conceptually explaining the structure of the fixed length format. In the figure, a plurality of blocks having the same size are continuously provided on the disk.
Each block is composed of a unique block address for identifying the block and a data section in which fixed-length block data is stored. When reading and writing block data with this fixed length format magnetic disk device, first, a block having a specified block address is searched. Then, if the corresponding block exists, the block data is continuously read and written for the data part included in the block.

As mentioned at the beginning, it is becoming more common to use fixed length format magnetic disk drives. Therefore, in order to effectively utilize the conventional software resources that were originally intended for variable-length format magnetic disk devices, is the fixed-length format magnetic disk device actually a variable-length format magnetic disk device? The emulation technology to be used like this is becoming important.

FIG. 9 is a diagram for conceptually explaining the process of mutually converting the format of variable-length record data and fixed-length block data. In the figure, the blocks of fixed length format shown in the lower stage are continuously provided in the cache memory. For more information on fixed format,
It is the same as that shown in FIG. Then, m blocks are subjected to format conversion in track units. In addition to the fixed-length format blocks described above, the variable-length format records shown in the upper part of the figure are continuously provided in the cache memory. The details of the variable length format are the same as those shown in FIG.

When the record data output from the host computer in the variable length format is recorded on the fixed length format recording / reproducing disk, the following processing is performed. That is, first, the host computer writes the variable-length record data as it is in the variable-length format track unit on the cache memory. The written record data is format-converted and written in fixed-length format track units on the cache memory. Then, the fixed-length block data is read again from the fixed-length format track unit, and is written on the fixed-length format recording / reproducing disk.

In the case of reproducing the record data of the variable length format used by the host computer from the block data recorded on the recording / reproducing disk as described above,
The following processing is performed. That is, m blocks corresponding to a track unit are read out collectively from the corresponding recording / reproducing disk first. Then, the read block data is directly written in the fixed-length format track unit on the cache memory. Then, based on this block data, variable-length record data before format conversion is reproduced in a variable-length format track unit on the cache memory. The host computer uses the necessary record data by referring to the variable-length format track unit on the cache memory.

[0009]

In the above conventional technique, when the host computer updates the record data, the following processing is performed. That is, first, in response to an instruction from the host computer, a track unit including record data to be updated is read from the corresponding recording / reproducing disc. By the reproduction processing described above, the variable-length record data before the format conversion is reproduced in the variable-length format track unit on the cache memory. The host computer performs necessary processing by using the reproduced variable-length record data, and then writes the updated record data in the same variable-length format track unit on the cache memory. Then, the updated data is converted into fixed-length block data by the above-described recording processing and then written back on the recording / reproducing disk.

At this time, if the update processing completion report is sent to the host computer after the writing back of the data to the recording / reproducing disk is completed, the system update processing performance causes the variable-length record data to be immediately written as it is. It deteriorates more than the long format magnetic disk drive. Therefore,
Immediately after the update process for variable-length record data in the cache memory is completed, the update process end report is sent,
After that, it is practically indispensable to avoid the above-mentioned deterioration of the update processing performance by the write-after control of converting the format of the data and writing back to the recording / reproducing disk.

In the system employing the above-mentioned write-after control, some trouble occurs between the completion of the update processing report to the host computer and the completion of the write-back to the recording / reproducing disk. Then, it is impossible for the host computer which has already received the update processing end report to instruct the processing corresponding to the failure.
In this case, if the cause of the failure is an abnormality of the recording / reproducing disk, the magnetic disk device itself can perform the conventional replacement block allocation process and normally terminate the write-back operation. However, if the cause of the failure is in the controller of the magnetic disk device, the interface controller, the interface path, etc., writing to the magnetic disk device itself becomes impossible, so the update processing completion report has already been sent to the host computer. Despite this, there is a problem that the validity of the data on the recording / reproducing disk that has been subject to the update process cannot be maintained.

Therefore, an object of the present invention is to solve the above problems and provide a recording control system which can always maintain the correctness of the data on the recording / reproducing disk regardless of the location and the time of the failure. Especially.

[0013]

In order to achieve the above object, a recording control system of the present invention comprises a data recording / reproducing apparatus for recording / reproducing a fixed length format recording / reproducing disk and a variable length format recording / reproducing disk. It is equipped with a data format conversion device that performs data format conversion with a conversion table on the cache memory according to the assumed recording / playback instruction from the host computer, and the actual writing process on the disk is based on the writing completion report to the host computer. In a recording control system to be performed later, a conversion table save area for temporarily saving the contents of the conversion table is provided in each of the data recording / reproducing devices, and is updated in the conversion table according to the recording / reproducing instruction. Write-back processing of the recorded data to the data recording / reproducing device If always not performed, it is obtained so as to retract the contents of the conversion table to the conversion table save area provided in different normal data recording and reproducing apparatus.

Then, at the time of initial startup of the system main body after the recovery of the failure, all conversion table save areas provided in each data recording / reproducing apparatus are checked and the saved contents of the conversion table are checked. The data is read into the cache memory.

Therefore, when the write-after control is performed, after the update processing completion report of the record data on the cache memory is reported to the host computer, some failure occurs in the disk controller, the interface controller, the interface path, etc. Occurs,
Therefore, when the write-back process of the block data obtained by the format conversion from the record data to the data recording / reproducing apparatus is not normally performed, it is different from the original data recording / reproducing apparatus which should record the block data. The contents of the conversion table including the block data are saved in the conversion table save area provided in the different data recording / reproducing apparatus. Then, when the system is first started after performing the necessary failure recovery processing, the contents of the conversion table saved in the conversion table save area are read back into the cache memory and are subject to write-after control. The validity of the data on the recording / reproducing disk can always be maintained regardless of the location of the failure and the time of occurrence.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a recording control system of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram schematically showing an embodiment of a recording control system of the present invention. In the figure, the host computer 11 and the recording control system 12 are connected. And the recording control system 1
Reference numeral 2 includes a data format conversion device 13, a cache memory 14, disk interface control devices 16a and 16b, disk control devices 17a to 17f, fixed length format disk devices 18a to 18f, and a battery device 1A.

The data format converter 13 is connected to disk interface controllers 16a and 16b. The disk interface control device 16a is connected to the disk control devices 17a, 17b, 17c via the general-purpose interface 15.
Further, the disk interface controller 16b is connected to the disk controller 17 via the general-purpose interface 15.
d, 17e and 17f are connected. The disk interface control devices 16a and 16b send control commands for accessing the disk devices to the respective disk control devices 17a to 17f, or receive status information and the like.

Fixed length format disk devices 18a to 18f are connected to the disk control devices 17a to 17f in association with each other. These disk control devices 17a to 17f perform positioning control, read control, write control, etc. necessary for accessing data on a recording / reproducing disk which is a recording medium for the corresponding fixed length format disk devices 18a to 18f. To do. The data format conversion device 13 is connected to the battery device 1A via a control line 19. The data format conversion device 13 includes a disk device 18 for updated data held in the cache memory 14.
The backup of the recording control system 12 by the battery device 1A is controlled so that the data is not lost by the time the writing back to a to 18f is completed.

FIG. 2 is a diagram showing an example of a specific configuration of the conversion table provided on the cache memory 14 in FIG. Hereinafter, the case where the record data in the variable length format and the block data in the fixed length format are format-converted by this conversion table will be described. In the figure, as a conversion table, a track data management table 20 and a track data 26 are stored in the cache memory 14.
Is provided. Further, the area for storing n tracks of the variable length format is determined in advance so that the memory address and the capacity are an integral multiple of the fixed length format. A unique track data area number 21 of 1 to n is assigned to each area. Then, these areas are registered in the track data management table 20. Further, the track information 22 corresponding to each area is stored in the track data management table 20. The track information 22 includes a device number 23, a cylinder / head number 24, and track data update information 25.

The device number 23 is a number that identifies one of the disk devices 18a to 18f in which the track including the data of the variable length format is stored. Device numbers 0 to 5 are associated with the respective disk devices 18a to 18f. Cylinder head number 24
Is a number that identifies the track in which the track data 26 corresponding to the track data area number 21 is stored in the disk device with the device number 23. The track data update information 25 is data indicating the state of updated data in the corresponding track. That is, the set value of the track data update information 25 is "1" when there is updated data and writing back to the disk device is not completed, and when there is no updated record and when writing to the disk device. '0' when the return is complete
It is. The track data 26 is composed of n track data 1 to n indicated by the track data area number 21 described above.

FIG. 3 shows the disk devices 18a to 18a in FIG.
It is a figure which shows an example of the specific structure of the conversion table save area provided in 18f. In the figure, the alternate track area 30
Is the disk interface controller 16a and 16
In the conversion table save area for temporarily saving the corresponding track data when the track data in the cache memory 14 cannot be written back to the disk device 18 due to a failure in the disk controller 17a to 17f or the like. is there. The alternate track area 30 includes an alternate track area management table 31 and an alternate track data area 32. Of these, alternate track area management table 3
1 includes a table identification pattern 33 and alternate track area management data 34. The alternate track area management data 34 includes a device number 35, an alternate track number 36, and an alternate track data storage address 37.

The table identification pattern 33 is a data pattern for determining whether or not the alternate track area 30 exists in the corresponding disk device of the fixed length format disk devices 18a to 18f. The table identification pattern 33 does not exist in the disk devices 18a to 18f in the initial state, and is written under the control of the data format conversion device 13 when the recording control system 12 is powered on to start the system. The device number 35 is a device number that identifies the original disk device in which the track data to which the alternate track has been allocated was previously stored. As in the case of FIG. 2, device numbers 0 to 5 are associated with the disk devices 18a to 18f, respectively. The alternate track number 36 is data indicating the number of alternate tracks actually assigned to the disk device identified by the device number 35. The alternate track data storage address 37 is set to the logical block number in which the alternate track data 38 in the corresponding disk device is stored. At this time, if the set value of the alternate track number 36 is zero, the alternate track data storage address 37 is also set to zero.

Next, the alternate track data area 32 will be described. The alternate track data area 32 is composed of a plurality of alternate track data 38. Each alternative track data 38 is composed of an alternative track index 39 and an alternative track 3C. Alternate track index 3
Reference numeral 9 is composed of a cylinder head number 3A and an alternate track storage destination NEXT address 3B. Here, the cylinder head number 3A is the cylinder head number of the track data to which the alternate track is assigned,
The alternate track storage destination NEXT address 3B is a logical block number in the disk device in which the following alternate track data is stored. For example, in the case of FIG. 3, the alternate track storage destination NEXT address 3B in the alternate track index 3Ba in the alternate track data 38a.
“A” indicates the logical block number in which the succeeding alternate track data 38b is stored. If there is no subsequent track data and the next replacement track data is not stored, the replacement track storage destination NEXT
The address 3B is set to zero. Alternate truck 3C
Is the same as the setting content of the track data 26 on the cache memory 14.

The normal operation of the system shown in FIG. 1 will be described below.

First, the access operation in the variable length format disk device and the access operation in the fixed length format disk device will be described. The variable length format is the data format shown in FIG. 7, and each record is stored in track units on the magnetic disk. Therefore, access to the target record is performed by the following procedure. That is, the cylinder head number in which the track containing the target record is stored is transferred from the host computer to the disk controller. The disk controller positions the recording / reproducing head on the target track of the magnetic disk based on the transferred cylinder head number. A record ID that identifies the target record is transferred from the host computer to the disk controller. The disk control device searches for a target record on the track based on the transferred record ID. The read / write process instructed by the host computer is performed on the searched target record.

On the other hand, the fixed length format is the data format shown in FIG. 8, in which one fixed length record is made to correspond to one logical block and is continuously stored on the magnetic disk. Then, continuous logical addresses are assigned to the respective logical blocks.
Therefore, access to the target record is performed by the following procedure. That is, the logical block address of the block corresponding to the first record storing the target data and the number of blocks to be accessed are transferred from the host computer to the disk controller. The disk control device searches for the first record in which the target data is stored based on the transferred logical block address. The disk control device performs the read / write processing instructed by the host computer on the block data of the designated block number from the retrieved record based on the transferred block number.

Next, the access operation in the system of FIG. 1 in which the variable length format data is stored in the fixed length format disk device will be described with reference to FIG. In the figure, the track data in which a plurality of variable-length format record data are collected for each track unit of a predetermined size is equally divided into a plurality of fixed-length blocks, and the fixed-length format disk devices 18a-18 are provided.
It is stored in f. When attempting to access the record data of the desired variable length format, first select the cylinder of the track containing the record data.
The head number is transferred from the host computer 11 to the data format conversion device 13. The data format converter 13 determines the logical block address in the disk device in which the track is stored, based on the transferred cylinder head number. Then, the data format conversion device 13 issues an instruction to read a plurality of block data corresponding to the capacity of the variable length format in track units from the obtained logical block address via the disk interface control device 16a or 16b. Transfer to. Upon receiving this, the disk control device reads m block data from the designated first logical block address in the fixed-length format disk device under control, and reads this m block data.
Transfer to 4. The data format conversion device 13 reconstructs the variable-length format track data from the m block data transferred to the cache memory 14. Then, the target record is searched from the track data, necessary reading / writing is performed on the corresponding record, and the result is transmitted to the host computer 11 as an end report. At this time, when the record data of the variable length format is written and the record data is updated, the apparent after-record is performed by performing the write-after control to write the updated record data to the disk device after the end report to the host computer 11. It is possible to speed up the write processing.

When actually writing the updated record data to the fixed-length format disk device, the cylinder head number 2 in the track information 22 of the track data read into the cache memory 14 before the update is used.
Refer to FIG. And this cylinder head number 24
From the logical block address in the disk device in which the track including the updated record data is stored. Further, an instruction to write block data of the number of blocks corresponding to the track capacity of the variable length format from the obtained logical block address is issued via the disk interface control device 16 to the disk control devices 17a ...
17f. In response to this, the disk control device reads the block data obtained by dividing the track containing the updated record data in the cache memory 14 into fixed length blocks, and specifies the specified logical block address in the fixed length format disk device under control. To write a plurality of block data corresponding to the capacity of each track of the variable length format. By the above, the actual writing of the updated data to the fixed length format disk device is completed.

FIG. 4 is a flow chart showing the flow of the save processing of the contents of the conversion table, which is performed when a failure occurs in the write-after control. When an attempt is made to write the updated data to the fixed length format disk device 18a by write after control, a failure occurs in either the disk interface control device 16a or the disk control device 17a, and the fixed length format disk device 18a. The case where the actual data writing to the memory becomes impossible will be described with reference to FIGS.

First, either the disk interface controller 16a or the disk controller 17a is in the middle of write-after control after the write-back completion report of the updated data in the cache memory 14 is sent to the host computer 11. It is detected that a failure has occurred and it becomes impossible to write back the corresponding data to the fixed length format disk device 18a (step 401). In response to this, the data format conversion device 13 selects the disk device 18b to which the device number "1" next to the device number "0" for identifying the fixed length format disk device 18a is assigned (step 402).
Then, the process (after step 403) of allocating the alternate track which is the conversion table saving area is started for the disk device 18b.

In step 403, the data format conversion device 13 causes the alternate track management table 31 provided in the fixed length format disk device 18b.
Is read into the cache memory 14. Then, the total number of alternate tracks in the alternate track management data 34 in the fixed-length format disk device 18b is 36a ...
The value of 36 m is summed up to calculate the current total number of replacement allocations. Also, track information 22 in the cache memory 14
For the device number 23a and the device number 35a included in, the set value of the corresponding alternate track number 36a is checked. As a result, the total number of replacement allocations = 0
If the number of alternate tracks is 36a = 0, the address of the alternate track data 38a (the start address of the track data area 32) is stored in the alternate track data storage address 37a. Next, the cache memory 14
Cylinder head number 3 in the upper alternate track area 30
Aa and the alternate track storage destination NEXT address 3Ba are generated. The cylinder head number 3Aa is the device number 2 in the track information 22 on the cache memory 14.
The cylinder head number 24a corresponding to 3a is stored. In the alternate track storage NEXT address 3Ba,
The initial value 0 is stored. After writing the cylinder head number 3Aa and the alternate track storage destination NEXT address 3Ba described above into the alternate track index 39a in the fixed length format disk device 18b, the track data 26a to be saved is written into the corresponding alternate track 3Ca, Complete the alternate track allocation process.

Subsequent to step 403, it is checked whether the writing of the alternate track index 39a and the alternate track 3Ca to the fixed-length format disk device 18b has been completed normally (step 404). When the process is normally completed (step 404 = YES), the value of the alternate track number 36a in the alternate track management data 34 transferred to the cache memory 14 is incremented (+1).
Then, the replacement track management table is updated (step 405). Then, the track data management table 20
The device number 23b and the following are checked to see if other track data including updated data to be written to the disk device 18a exists in the track data 26 (step 406). As a result, when there is no other track data (step 406 = N)
O), the alternate track management table 31 in which the contents to be saved is set is written in the disk device 18b (step 407), and the track area in which the track data of the original disk device 18a in which the updated data should be written back is stored The track data update information 25a to 25n in the track information 22 corresponding to the numbers 21a to 21n are
All are set to "0" and the alternate allocation process for the fixed length format disk device 18a is completed (step 408). On the other hand, if other track data exists (step 406 = YES), step 403 is executed again.
Return to and repeat the alternate track assignment process.

The specific processing operation in step 403 will be described below. That is, if the track data 26c includes the track data including the updated data that should be originally written in the disk device 18a, the alternate track number 36a = 1 and the alternate track number 36.
The total number of replacement allocations, which is the sum of all, is 1. And
In the alternate track area 30 on the cache memory 14, the cylinder head number 3Ab and the alternate track storage destination NEX
The T address 3Bb is generated. Track information 2 in the cache memory 14 is stored in the cylinder head number 3Ab.
The cylinder head number 24c corresponding to the device number 23c in 2 is stored. An initial value of 0 is stored in the alternate track storage destination NEXT address 3Bb. Then, the cylinder head number 3Ab and the alternate track storage destination NEXT address 3Bb described above are used as the alternate track index 39b in the fixed length format disk device 18b.
After writing the data into the cache memory, the track data 26c to be saved is written into the corresponding alternate track 3Cb, and when the process is completed normally, the alternate allocation number 36a in the cache memory 14 is written.
The value of is incremented (+1). Subsequently, the alternate track index 39a is calculated from the logical block address indicated by the alternate track data storage address 37a.
Is read on the cache memory 14. Then, after storing the next alternate track data address 38b in the alternate track storage destination NEXT address 3Ba in the alternate track index 39a, these are stored in the disk device 18b.
Write back to When the alternate allocation process for the fixed length format disk device 18a is completed as described above, the alternate track management table 31 is written back to the fixed length format disk device 18b.

In step 404, track data 2
If the writing of the replacement track No. 6 to the replacement track 3C is abnormally ended, the replacement track management table 31 on the cache memory 14 is not written to the disk device (for example, the disk device 18b), and the replacement allocation device number is incremented at step 404a. As a result, the fixed-length format disk device to be written is changed (for example, the disk devices 18b → 18c), and the alternate allocation process is performed again. By performing this control, it is possible to prevent the same track data from being alternately assigned to a plurality of fixed length format disk devices.

When the alternate allocation processing is completed by the above write-after control, the recording control system reports to the host computer 11 that a failure has occurred, and either the disk interface control devices 16a, 16b or the disk control device 17a. Request replacement of the failed part of 17f.

FIG. 5 and FIG. 6 are flowcharts showing the flow of the process of reading the contents of the saved conversion table, which is performed at the time of initial startup after the restoration of the fault. The contents of the conversion table saved in the alternate track when a failure occurs when the recording control system is powered off and the system is started again after the recording control system is turned off and parts are replaced To load (load)
The processing will be described with reference to FIGS. 1 to 3, 5 and 6.

When the initial operation at the time of system startup (step 501) is completed and the system is in an operating state, all the connected fixed length format disk devices 18a to 18f are processed by the processing of steps 502 to 507.
From inside, the contents of the alternate track area management table 31 are read onto the cache memory 14. That is, first, the device number "0" of the head disk device 18a connected is set to the access target device number from which the alternate track area management table 31 is to be read (step 502). Then, with respect to all the disk devices 18a to 18f, it is judged whether or not reading = loading of the alternate track area management table 31 onto the cache memory 14 is completed (step 503). As a result, when the loading of all the tables is not completed (step 503 = NO), the alternate track area management table 31 is read from the disk device indicated by the access target device number (step 504). Then, it is checked whether or not there is a valid table identification pattern 33 in the read alternate track area management table 31 (step 505). If the table identification pattern 33 is invalid (step 505 = NO), a new alternative track area management table 31 is newly generated, and the alternative track number 36 and the alternative track data storage destination in the alternative track management data 34 are stored. The initial value "0" is set for both the addresses 37 (step 506). As described above, loading of the table is completed for one disk device, so the access target device number is incremented (step 507) and the process returns to step 503 again.

When reading / loading of the alternate track area management table 31 onto the cache memory 14 is completed for all the disk devices 18a-18f (step 503 = YES), all disks are processed by the processing of steps 511-516. The cache memory 14 stores the contents (contents of the conversion table saved at the time of failure) of the alternate track 3C stored in the devices 18a to 18f.
Read up. That is, first, the replacement truck 3C
The device number "0" of the head disk device 18a connected is set to the alternate track load target device number to be read (step 511). Then, with respect to all the disk devices 18a to 18f, it is judged whether or not the reading / loading of the alternate track 3C onto the cache memory 14 is completed (step 51).
2). As a result, when the loading of all the tracks is not completed (step 512 = NO), the alternate track area management table 31 of the disk device indicated by the alternate track load target device number on the cache memory 14
With reference to, the value of the alternate track number 36 corresponding to the corresponding device number 35 in the alternate track management data 34 is checked (step 513). For example, if the alternate track load target device number is "0", the value of the alternate track number 36a corresponding to the device number 35a is checked. As a result, when the value of the alternate track number 36a is not zero (step 514 = YES), the alternate track 3C is transferred from the disk device indicated by the device number 35a.
Alternate track load processing is performed to read the data into the cache memory 14 (step 515). As a result, the loading of the alternate track for one disk device is completed, so the alternate track loading target device number is incremented (step 516) and the step 51 is performed again.
Return to 2. When the value of the alternate track number 36 is zero (step 514 = NO), step 515 is skipped, the alternate track load target device number is incremented (step 516), and step 5 is performed again.
Return to 12.

The alternate track loading process of step 515 will be described below. First, cache memory 1
4, the alternate track area management table 31 is read out, and the alternate track index 39a is read from the address indicated by the alternate track data storage destination address 37a in the alternate track management data 34. Then, the alternate track is read from the disk device and stored in the track data 26a in the cache memory 14. Then, the device number 23a, the cylinder head number 24a, and the track data update information 25a corresponding to the alternate track stored in the track data 26a.
To, set the value respectively. The set values are the device number 35a of the alternate track data 34 for the device number 23a, and the cylinder head number 3 of the alternate track index 39 for the cylinder head number 24a.
Aa is "1" indicating that the track data includes update data for the track data update information 25a.

As a result of repeating the above processing, when the loading of all tracks is completed (step 512 =
If YES, the replacement track management data 34 is cleared for all the disk devices 18a to 18f (step 521). As a result, the cache memory 1
In the alternate track management data 34 on No. 4, zero is set for both the alternate track number 36 and the alternate track data storage destination address 37. Finally, the contents of the alternate track area management table 31 on the cache memory 14 are written back to all the fixed-length format disk devices 18a to 18f, and the update data that was not normally written back when the failure occurred Complete the actual writeback of.

According to the above-described embodiment, when the write-after control is performed, after the update processing completion report of the record data on the cache memory is sent to the host computer, the disk controller, the interface controller, the interface If some kind of failure occurs in the path, etc., and the block data obtained by format conversion from the above record data is not written back to the data recording / reproducing device (disk device) normally, the above block data is deleted. The contents (track data) of the conversion table including the block data are saved in a conversion table save area (alternate track data area) provided in a normal data recording / playback apparatus different from the original data recording / playback apparatus to be recorded. It And
When the system is started for the first time after performing the necessary failure recovery processing, the contents of the conversion table saved in the conversion table save area are read back into the cache memory and are subject to write-after control. It is possible to always maintain the legitimacy of the data on the recording / reproducing disc, regardless of the occurrence point or the occurrence point of.

[0043]

As described in detail above, according to the recording control system of the present invention, when the write-after control is performed, the update completion report of the record data on the cache memory is sent to the host computer. After that, some failure occurs in the disk controller, interface controller, interface path, etc.,
Therefore, when the write-back process of the block data obtained by the format conversion from the record data to the data recording / reproducing apparatus is not normally performed, it is different from the original data recording / reproducing apparatus which should record the block data. The contents of the conversion table including the block data are saved in the conversion table save area provided in the different data recording / reproducing apparatus. Then, when the system is first started after performing the necessary failure recovery processing, the contents of the conversion table saved in the conversion table save area are read back into the cache memory and are subject to write-after control. Therefore, regardless of the occurrence location and the occurrence time point of the failure, it is possible to always maintain the validity of the data on the recording / reproducing disk.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing an embodiment of a recording control system of the present invention.

FIG. 2 is a diagram showing an example of a specific configuration of a conversion table provided on the cache memory in FIG.

FIG. 3 is a diagram showing an example of a specific configuration of a conversion table save area provided in each disk device in FIG.

FIG. 4 is a flowchart showing a flow of a save process of contents of a conversion table performed when a failure occurs in write after control.

FIG. 5 is a flow chart (No. 1) showing a flow of a load process of contents of a conversion table performed at the time of initial startup after failure recovery.

FIG. 6 is a flowchart (No. 2) showing the flow of the load processing of the contents of the conversion table performed at the time of initial startup after the restoration of the failure.

FIG. 7 is a diagram for conceptually explaining the configuration of a variable length format.

FIG. 8 is a diagram for conceptually explaining the structure of a fixed length format.

FIG. 9 is a diagram conceptually illustrating a process of mutually converting the format of variable-length record data and fixed-length block data.

[Explanation of symbols]

11 Host Computer 12 Recording Control System 13 Data Format Converter 14 Cache Memory 15 General Purpose Interface 16a, 16b Disk Interface Controller 17a, 17b to 17f Disk Controller 18a, 18b to 18f Fixed Length Format Disk Device 19 Control Line 1A Battery Device

Claims (2)

[Claims] 1. A data recording / reproducing apparatus for recording / reproducing a fixed-length format recording / reproducing disk, and a conversion table on a cache memory for storing data in response to a recording / reproducing instruction from a host computer assuming a variable-length format recording / reproducing disk. In a recording control system, which comprises a data format conversion device that performs format conversion and in which the actual writing process on the disk is performed after the writing completion report to the host computer, to temporarily save the contents of the conversion table. The conversion table save area is provided in each of the data recording / reproducing devices, and the process of writing back the data updated in the conversion table to the data recording / reproducing device according to the recording / reproducing instruction was not normally performed. Provided in different normal data recording / reproducing device Recording control system is characterized in that so as to retract the contents of the conversion table to the conversion table save area. 2. Upon initial startup of the system main body after recovery from the failure, all conversion table save areas provided in each data recording / reproducing device are checked and the contents of the saved conversion table are checked. 2. The recording control system according to claim 1, wherein the recording control system is read on the cache memory.