JP2002222063A - Disk array device and its data restoring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk array device and its operating method which can shorten the time needed to restore data when one of the disk drives constituting the disk array device gets out of order and is replaced. SOLUTION: When a disk array control part 2 receives a write instruction, an address computation part 11 computes the final address of the instruction and a comparison part 13 compares the final address of the current instruction with the value of a count part 12 where the maximum final address among instructions processed in the past is written. When the address of the current instruction is larger than the recorded address, the address is written to the count part 12, but when not, it is ignored. When the disk array device needs to be subjected to restoration processing, only the part where data up to the address of the count part 12 are written is restored to shorten the time needed for the restoration processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk array device and a data restoring method therefor, and more particularly to a data restoring processing technique required when replacing a disk drive in a disk array device widely used as a data storage device in an information processing device. About.

[0002]

2. Description of the Related Art A disk array device is composed of a plurality of disk devices (or disk drives), and data is recorded on the plurality of disk devices together with redundant data. In the disk array device having such a configuration, one of a plurality of disk devices constituting the disk array device should be used.
Even if a failure occurs in the table, data can be restored by the remaining disk devices, and high reliability can be obtained. Therefore, the disk array device having the above configuration is widely used.

[0003] The prior art of such a disk array device is as follows.
For example, Japanese Patent Application Laid-Open No. 5-88988, “Disk Array Apparatus and Data Restoration Method”, and Japanese Patent Application Laid-Open No. 11-248
No. 49, "Disaster Recovery Method and Apparatus" and the like. In the latter conventional disk array device, unless data is restored in a complicated manner, restoration must be performed for all disk devices including unused portions (or unused areas) unless complicated control is performed. . During the restoration processing of the conventional disk array device, the access performance from the upper layer is reduced, and furthermore, since there is a high possibility of losing recorded data due to the loss of redundancy, the data restoration processing time as short as possible is desired. It is.

[0004]

In the conventional disk array device as described above, each time the specification of the file management information written by the OS (operating system) of the host device changes, the disk array device also changes in accordance with the specification change. Is required. Therefore, there is a problem that the hardware required by the disk array device that can be used for various OSs in general can be of a certain scale.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve or reduce the above-mentioned problems, to provide a disk array device which is simple and controllable without being affected by the specifications of a higher-level device, and has simple hardware, and its data restoration. It is to provide a method.

[0006]

A disk array device according to the present invention comprises a disk array control unit for decoding commands received from a host computer and performing necessary control, a plurality of disk control units, and a plurality of disk devices. An apparatus comprising: an address calculation unit that calculates a final address of a write instruction; a count unit that writes a final address; and a comparison unit that compares values of the address calculation unit and the count unit. According to a preferred embodiment of the present invention, the address calculation unit, the count unit, and the comparison unit are provided in the disk array control unit in common with the plurality of disk control units and the plurality of disks. Also, a plurality of address calculation units, counting units, and disk control units are provided for each of the plurality of disk devices.

Further, according to the data restoring method of a disk array device of the present invention, in a disk array device including a disk array control unit, a plurality of disk control units, and a plurality of disk devices, any one of the plurality of disk devices is used. In the case of replacement, when restoring the data of the disk device to be replaced, the data recovery portion is limited and the recovery of the unused area is avoided, thereby shortening the time required for the recovery. According to the preferred embodiment of the present invention, the maximum address of a write request is always stored in the counting unit, and when a recovery process is performed due to a disk device failure or the like, the writing held in the counting unit from the beginning of the disk device is performed. The user data up to the last address is restored.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and operation of a preferred embodiment of a disk array device and a data restoration method thereof according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a configuration of a first embodiment of a disk array device according to the present invention. The disk array device of the first embodiment is used together with a host computer 1, and includes a disk array controller 2, a plurality of disk controllers 3A to 3D, and a plurality of disk devices (including at least one redundant disk device) 4A to 4A. 4
D. The disk array control unit 2 includes:
Address calculation unit 11, counting unit 12, and comparison unit 13
Is connected. The address calculator 11 calculates a final address. The counting unit 12 writes the last address. The comparing unit 13 compares the values of the address calculating unit 11 and the counting unit 12 and writes the larger value into the counting unit 12. In the first embodiment, a case will be described in which four disk devices 4A to 4D are used. However, the present invention is not limited to the number of disk devices, and is applicable to a case where three or five or more disk devices are used. Is also applicable.

In the above-described disk array device, the disk array control unit 2 decodes a command received from the host computer 1 and, at the time of a write command, transmits data received from the host computer 1 to a plurality of disk control units 3.
Distribute and send to A to 3D. Then, the plurality of disk controllers 3A to 3D cause the corresponding disk devices 4 to correspond to each other.
Write to A-4D.

If the command received from the host computer 1 is a read command, the disk devices 4A to 4A
The data written in 4D is sent to the corresponding disk control units 3A to 3D. Then, the data is returned to the single data by the disk array control unit 2 and sent to the host computer 1.

On the other hand, when the disk array controller 2 receives a write command from the host computer 1, the address calculator 11 calculates the final address of the write command. Further, the comparing unit 13 compares the value written in the counting unit 12 with the last address from the address calculating unit 11. If the value calculated by the address calculation unit 11 is smaller than the value of the counting unit 12, the value of the counting unit 12 is not updated. If the value calculated by the address calculating unit 11 is larger than the value of the counting unit 12, the calculated value is recorded in the counting unit 12 and a write command is executed.

Next, for example, when a failure or the like occurs in the disk device 4A and the disk device 4A needs to be replaced,
A is exchanged, and the data of the disk devices 4B to 4D are transferred to the disk array controller 2 through the disk controllers 3B to 3D.
To calculate the data to be written to the disk device 4A, and calculate the data to be written to the disk device 4A through the disk controller 3A.
A restoration processing for writing to A is performed. Here, the disk array control unit 2 continues the restoration process until the address to be written to the disk device 4A reaches the value of the count unit 12, and restores the portion (unused area) of the subsequent disk array device that has not been written. Not performed.

FIG. 2 is a block diagram showing the configuration of a disk array device according to a second embodiment of the present invention. Note that the same reference numerals are used for the components corresponding to the components in FIG. 1 for convenience. The disk array device of the second embodiment includes a disk array control unit 2, a plurality (four in the illustrated example) of disk control units 3A to 3D, and a plurality of disk devices 4A to 4D. Here, the disk control units 3A to 3D include an address calculation unit 11A to 11D, a count unit 12A to 12D for holding the last address, and an address calculation unit 1 respectively.
Address comparing units 13A to 13D are connected to compare the values of 1A to 11D and the values of the counting units 12A to 12D and write the larger value into the counting units 12A to 12D. still,
In the second embodiment, a case in which four disk devices 4A to 4D are used will be described. However, it is needless to say that the present invention can be applied to a case in which three or five or more disk devices are used.

In the disk array device shown in FIG.
The disk array controller 2 decodes a command received from the host computer 1. At the time of the write command, the data received from the host computer 1 is distributed to a plurality of disk controllers 3A to 3D and sent, and the plurality of disk controllers 3A to 3D respectively transmit the corresponding disk devices 4A to 4D.
Write to 4D.

On the other hand, when the command received from the host computer 1 is a read command, the disk devices 4A to 4A
The data written in 4D is sent to the corresponding disk control units 3A to 3D. Then, the data is returned to the host computer 1 by the disk array control unit 2.

When the disk array controller 2 receives a write command, it issues a write command to the disk controllers 3A to 3D. At this time, in the disk controller 3A, the address calculator 11A calculates the final address of the write command. Then, the comparing unit 13A includes the counting unit 12A.
Is compared with the last address from the calculation unit 11A. If the value calculated by the calculating unit 11A is smaller than the value of the counting unit 12A, the value of the counting unit 12A is not updated. On the other hand, if the value calculated by the calculating unit 11A is larger than the value of the counting unit 12A, the calculated value is recorded in the counting unit 12A and the write command is executed.

Hereinafter, the disk control unit 3B, the address calculation unit 11B, the count unit 12B, the comparison unit 13B, the disk control unit 3C, the address calculation unit 11C, and the count unit 12
The combination of C, the comparison unit 13C, the disk control unit 3D, the address calculation unit 11D, the count unit 12D, and the comparison unit 13D operates in the same manner as described above.

Next, for example, when a failure occurs in the disk device 4A and the disk device 4A needs to be replaced,
Replace A. Then, the data of the disk devices 4B to 4D are transmitted to the disk array control unit 2 through the disk control units 3B to 3D, the data to be written to the disk device 4A is calculated by calculation, and the restoration process of writing to the disk device 4A through the disk control unit 3A. Execute Here, the disk array control unit 2 continues the restoration processing until the address to be written to the disk device 4A reaches the value of the counting unit 12A. Restoration is not executed for a portion where no data is written as a subsequent disk array device.

The configuration and operation of the preferred embodiment of the present invention have been described above in detail. However, it should be noted that such an embodiment is merely an example of the present invention and does not limit the present invention in any way. Those skilled in the art can easily understand that various modifications can be made depending on the specific application without departing from the gist of the present invention.

[0021]

As will be understood from the above description, the disk array apparatus of the present invention and the data restoring method thereof have the following remarkable practical effects. In a disk array device composed of a plurality of disk devices including at least one redundant disk device, the time required for the restoration process with a smaller number of additional circuits is not affected by the specifications of the higher-level device as disclosed in the above-described related art. Can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of a disk array device according to the present invention.

FIG. 2 is a block diagram showing a configuration of a second embodiment of the disk array device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Host computer 2 Disk array control part 3 Disk control part 4 Disk device 11 Address calculation part 12 Count part 13 Comparison part

Claims (5)

[Claims] In a disk array device including a disk array control unit that decodes a command received from a host computer and performs necessary control, a plurality of disk control units, and a plurality of disk devices, a final address of a write command is determined. A disk array device comprising: an address calculating unit for calculating; a counting unit for writing a final address; and a comparing unit for comparing values of the address calculating unit and the counting unit. 2. The disk array control unit according to claim 1, wherein the address calculation unit, the counting unit, and the comparison unit are provided commonly to the plurality of disk control units and the plurality of disk devices. The disk array device according to item 1. 3. The disk array device according to claim 1, wherein a plurality of said address calculation units, said counting units and said comparison units are provided for each disk device. 4. A disk array device comprising a disk array control unit, a plurality of disk control units, and a plurality of disk devices, wherein when any one of the plurality of disk devices is replaced, the disk device to be replaced is replaced. A data restoring method for a disk array device, wherein when restoring data, a restoring time is reduced by limiting a restoring portion and avoiding restoring an unused area. 5. The method according to claim 5, wherein the maximum address of the write request is always stored in the counting unit, and when the failure recovery process is performed due to the occurrence of a failure in the disk device, the write held in the counting unit is read from the beginning of the disk device. 5. The method according to claim 4, wherein the user data up to the last address is restored.