JP2834081B2 - Magnetic disk controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk controller, and more particularly, to an FBA with a high write performance.
(Fixed Block Address form
at: fixed-length format) -CKD (Count K
eye Data format: variable length format)
The present invention relates to a magnetic disk control device that performs format conversion.

[0002]

2. Description of the Related Art A conventionally known example is disclosed in Japanese Patent Laid-Open No. 05-15 / 2005.
No. 0905 is known.

The conventional magnetic disk control device will be described with reference to the drawings.

FIG. 4 is a block diagram of a conventional magnetic disk controller for performing format conversion.

Conventionally, an FB is provided via a magnetic disk controller.
When writing data to an A-format magnetic disk device, the magnetic disk control device issues one write instruction to the magnetic disk device for realizing the operation of one instruction issued from the host device. By doing so, the writing process was realized.

[0006] The conventional magnetic disk control apparatus for performing format conversion shown in FIG. 4 has a data buffer unit 24 having a capacity sufficient to store data for one track, and a higher-level device for data writing or the like. By executing only the changed sector after processing the command from the data buffer unit 24 on the data unit 24, the execution performance of the write command is improved.

Further, in the conventional magnetic disk control apparatus for performing format conversion shown in FIG. 4, one track of data is stored in the data buffer unit 24 in advance in order to process a command issued from a host apparatus. Since the data must be read from the unit 31, a considerable overhead occurs. Therefore, in the magnetic disk control device that performs format conversion using the conventional technology, the data buffer unit 24 is configured as a data cache having a considerably large recording capacity in order to secure performance that can be used in a general-purpose computer. The overhead was reduced by reducing the number of accesses to the device.

[0008]

The first problem is that, when the FBA-CKD format conversion is executed in the magnetic disk control device, the CKD disk write command issued from the host device in units of records is continuously processed. In this case, if writing to the FBA disk is performed in units of records, a loss of one rotation always occurs every time one record is written, resulting in a significant decrease in performance.

The reason is that SCSI (Small Co.)
When the FBA disk is controlled using an interface such as an MPU (System System Interface), the time from command issuance to operation start and the time from operation end to result report are long, so that writing of continuous sectors by separate commands is performed. This is because, if an attempt is made to execute the process, the process cannot be performed in a gap between the sectors.

The second problem is that if a data cache is provided inside the magnetic disk controller to improve the write performance, the cache control becomes complicated and the size of the device becomes large, so that the device becomes considerably expensive. It is to be.

[0011] The reason is that, in an apparatus using a data cache, data transfer between a higher-level apparatus and the data cache is performed.
This is because, since the data transfer between the data cache and the FBA disk is separated, it is necessary to increase the hit ratio of the data cache and efficiently control the data writing to the FBA disk in order to improve the write performance. In other words, in order to increase the write performance by the method using the data cache, the capacity of the data cache must be increased, and at the same time, the update of the cache contents and the control of writing to the FBA disk become complicated. I have to have hardware for data caching.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the performance degradation of a write command without using a data cache, thereby achieving a small, small-volume, high-performance FBA-CKD format magnetic disk. It is to provide a control device.

Therefore, the magnetic disk control device of the present invention is provided with a means for instructing in advance the number of records to be continuously written from the higher-level device so that a plurality of records indicated by a plurality of write commands from the higher-level device can be provided. Is written by one write command to the FBA disk.

More specifically, a processing record number management means (1 in FIG. 1) for managing the number of records in the CKD format in which continuous writing is instructed from a higher-level device.
Format information management means (2 in FIG. 1) for storing format conversion information for recording data of a logical CKD track to be processed on an FBA disk; and upper interface control for transferring commands and data with a higher device. Means (4 in FIG. 1) and lower-level interface control means (5 in FIG. 1) for transferring commands and data between a lower-level device (FBA disk) independently of the higher-level device
And calculating the sector address and the number of sectors to be written to the FBA disk from the number of processed records indicated by the number of processed records management means (1 in FIG. 1) and the format conversion information of the format information management means (2 in FIG. 1). It has a format conversion control means (3 in FIG. 1) for instructing the number of data transfers, activation of data transfer and command issuance to the lower interface control means (5 in FIG. 1).

The number of records to be written by the host interface control means is received in advance from the host device as a command and stored in the processing record number management means, and thereafter a plurality of write commands and data are sequentially received from the host device.

When the head position of the record to be written is determined, the format conversion control means calculates the write start address and the number of write sectors on the FBA disk based on the information of the processing record number management means and the format information management means. Issues one write command to the FBA disk.

The lower interface control unit transfers the write data as soon as the write data request from the FBA disk and the write data from the upper interface control unit are prepared.

With the above operation, the write data transfer to the FBA disk is completed almost at the same time as the data transfer by a series of write commands from the host device is completed.

[0019]

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

The present invention can be realized not only in the FBA-CKD format conversion but also in a magnetic disk device for converting between the FBA format and a format other than the CKD format.
A description will be given taking A-CKD format conversion as an example.

FIG. 1 is a block diagram showing an embodiment of a magnetic disk control device according to the present invention.

The magnetic disk control device according to the present embodiment
A host device 6 for instructing the number of records in the CKD format for continuous writing by a command, a processing record number management unit 1 for managing the number of processing records instructed by the host device, and data of a logical CKD track to be processed Format information management means 2 for storing format conversion information for recording a file on an FBA disk, a high-level interface control means 4 for transferring commands and data with a high-level device, and a low-level device (FBA Lower-level interface control means 5 for transferring commands and data between the disk and the magnetic disk controller, and the number of processed records indicated by the processed record number managing means 1 and the format conversion information of the format information managing means 2 to write to the FBA disk. Calculate the sector address and the number of sectors. The format conversion control means 3 for instructing the interface control means 4 and the lower-level interface control means 5 for the number of data transfers, activation of data transfer and command issuance, and the FBA format magnetic disk devices (FBA disks) 7 to 10 It is configured.

It is assumed that the FBA disk is formatted at 512 bytes / sector.

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

FIG. 2 is a flow chart of a channel command issued from the higher-level device to the magnetic disk controller to write two continuous CKD format records, and FIG. 3 executes the channel command shown in FIG. FIG. 7 is a diagram showing a logical CKD track in a case and a format correspondence of data on an actual FBA disk.

When the channel command shown in FIG.
Of the FBA disk (7 in FIG. 1).

When the Seek command of the channel command is executed, the format conversion control means 3 stores information on the target logical track (Nth logical track) on the FBA disk with ID = 0 in the format information management means 2. It is checked whether or not the sector address exists, and if it does not exist, the sector address on the FBA disk corresponding to the head of the Nth logical track is calculated from the Seek data, and the sector n on the FBA disk 7 through the lower interface control means 5 (19 in FIG. 3). And reads out the format control information of the Nth logical track existing in the format information management means 2 (step 11).

It should be noted that the same data as that of the sector n is stored in the sector n + 1, and the data is compared to check the contents when reading the format information.

Set Record of channel command
The Count command is executed to indicate to the magnetic disk controller of the present invention the number of a series of records processed by the command executed thereafter. Number of records processed by this command (in this case, '0
2 ') is stored in the processing record number management means 1 (step 12).

Ex-Search of channel command
In response to the ID Equal command, the format conversion control means 3 refers to the format information management means 2 to determine the position of the record to be processed (record 1 in this case) on the FBA disk (step 13).

Next, Write D of the channel command
When the data conversion command is executed, the format conversion control means 3 determines the data portion of record 1 (1 in FIG. 3) from the execution result of the Ex-Search ID Equal command.
7) Recognizing that the instruction is a write instruction to the processing record number management means 1, and executing another write command for a continuous record from the information that the number of processed records stored in the processed record number management means 1 is two. Recognize. As a result, the format conversion control means 3 determines that the data portion of record 1 (17 in FIG. 3) and the data portion of record 2 (18 in FIG. 3) are continuously written by the currently executed channel program. Then, a write command to the FBA disk including a write to the data portion of record 2 to be executed after that is issued by 1
Is issued (step 14).

More specifically, the format conversion control means 3
Is the first sector address (n + 2) of the data portion of record 1 (17 in FIG. 3), the size of the data portion of record 1 (800 bytes), and the size of the data portion of record 2 (800 bytes). ) Is read, and the data portion of record 1 (17 in FIG. 3) and record 2
The first sector address and the number of write sectors for writing the data portion (18 in FIG. 3) by one command are calculated, and the lower interface control means 5 transfers the sector from sector n + 2 (20 in FIG. 3) to the FBA disk 7 from the sector n + 2. n
The command to write 4 sectors of +5 (23 in FIG. 3) is 1
Issue one.

When a write data transfer request is received from the FBA disk 7, the format conversion control means 3 sends the data to the high-level device 6 by the high-level interface control means 4 to the high-level device 6 with the size of the data portion of record 1 (17 in FIG. 3) of 800 bytes. , And instructs the lower-level interface control means 5 to perform write transfer of two 512-byte data blocks (sectors). When data from the higher-level device 6 arrives, the lower-level interface control means 5 receives the data from the higher-level interface control means 4 and sends it to the FBA disk 7.

Here, all data of 800 bytes, which is the size of the data portion (17 in FIG. 3) of the record 1, is transferred from the higher-level device 6, and the upper-level interface control means 4 writes the data to the lower-level interface control means 5. Upon notifying the end of the transfer, the lower interface control means 5 sends 224 bytes of '00' data to the sector n + 3 (21 in FIG. 3) as the remaining data less than 512 bytes, and ends the processing of the WriteData command. .

Ex-Search of channel command
When the ID command is executed, the format conversion control means 3 only confirms that the next record to be written indicated by the command 15 is a continuous record since the write command to the FBA disk is being executed (step S15). 15).

Write Data of Channel Command
When the command is executed, a transfer request of write data has already been received from the FBA disk 7, so that the format conversion control means 3 immediately executes the upper interface control means 4 and the lower interface control means as in the case of writing the record 1. 5 and receives the data of the data part (18 in FIG. 3) of the record 2 from the host device 6, and receives the sector n + 4 (22 in FIG. 3) and sector n + 5 (23 in FIG. 3).
The write data is transferred to the memory (step 16).

Thereafter, as in the case of sector n + 3 (21 in FIG. 3), 22 for sector n + 5 (23 in FIG. 3).
4 bytes of '00' data are sent out and Write Da
The processing of the ta command ends.

By the operation described above, a plurality of write commands from the upper device can be processed by one write command to the FBA disk according to the number of processing records instructed in advance by the upper device.

It is apparent that the present invention can be similarly realized in a control device of an external storage device having a control method similar to that of a magnetic disk device.

[0040]

The first effect is that a plurality of write commands from a higher-level device can be realized by one command to an FBA disk in a magnetic disk controller that performs format conversion. is there.
As a result, there is no rotation loss on the FBA disk caused by issuing a write command for continuous sectors on the FBA disk, and the write performance can be increased.

The reason is that there is provided a means for receiving and managing the number of records to be processed continuously from the host device before executing the write command.

A second effect is that in a magnetic disk control device for performing format conversion, it is possible to realize a high write performance with a relatively simple hardware configuration. This makes it possible to reduce the size of the device and reduce the price of the device.

The reason is that the writing performance is not increased by providing a large-capacity, high-performance data cache, but by providing a means for receiving and managing the number of records processed in advance from a higher-level device. Because he did.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a magnetic disk control device of the present invention.

FIG. 2 is a flowchart of a channel command issued from a higher-level device to the magnetic disk control device of the present embodiment.

FIG. 3 is a diagram showing a format correspondence between a logical CKD track and data on an actual FBA disk when each channel command of FIG. 2 is executed.

FIG. 4 is a block diagram illustrating an example of a conventional magnetic disk control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Processing record number management means 2 Format information management means 3 FBA / CKD conversion control means 4 Upper interface control means 5 Lower interface control means 6 Upper device 7 FBA disk (ID = 0) 8 FBA disk (ID = 1) 9 FBA disk (ID = 2) 10 FBA disk (ID = 3) 17 Data part of record 1 (CKD format) 18 Data part of record 2 (CKD format) 19 sector n (FBA sector corresponding to the head of the Nth logical CKD track) 20 sector n + 2 (FBA sector corresponding to the first half of the data part of record 1) 21 sector n + 3 (FBA sector corresponding to the second half of the data part of record 1) 22 sector n + 4 (FBA sector corresponding to the first half of the data part of record 2) ) 23 Sector n + 5 (Record FBA sector) 24 data buffer 25 format controller 26 buffer access control section 27 sector managing unit 28 writes the control unit 29 check code generation unit 30 data check unit 31 medium portion corresponding to the second half of the second data unit

Claims (1)

(57) [Claims] 1. A processing record number management means for managing the number of records in a CKD format in which continuous writing instructed by a higher-level device is performed, and data of a logical CKD track to be processed is recorded on an FBA disk as a lower-level device. Format information management means for storing format conversion information for performing the command, higher-level interface control means for transferring commands and data to and from the higher-level device; and commands and commands to and from the FBA disk independently of the higher-level device. A lower interface control unit for transferring data; calculating a sector address and a sector number to be written to the FBA disk from the number of processed records indicated by the processed record number managing unit and format conversion information of the format information managing unit; Control means and said lower interface Number of data transfer to Esu control means,
A magnetic disk control device comprising: a format conversion control unit that issues a command to start data transfer and issue a command.