STORAGE SYSTEM AND MEMORY DEVICE FAULT RECOVERY METHOD

• US 20150378858A1
• Filed: 02/28/2013
• Published: 12/31/2015
• Est. Priority Date: 02/28/2013
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: OGASAWARA, Tomohisa, TAKAMURA, Yukiyoshi, ISHIZAKA, Ryoma, MATSUMURA, Yusuke
• Application Number:
  US14/764,397
• Publication Number:
  US 20150378858A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1088 Reconstruction on already foreseen single or plurality of spare disks
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 2201/85 Active fault masking without idle spares active fault masking without idle spare hardware where processing functionality is redundant G06F11/2035

Abstract

The present invention aims at providing a storage system capable of shortening the recovery time from failure while ensuring the reliability of data when failure occurs to a storage device. When failure occurs to a storage device, a recovery processing corresponding to the content of failure is executed for the blocked storage device. The storage device recovered via the execution of the recovery processing is subjected to a check corresponding to the operation status of the storage system or the failure history of the storage device.

Claims

1. A storage system coupled to a host computer, the storage system comprising:

a controller;

a memory;

a plurality of data storage devices for storing data sent from the host computer; and

one or more spare storage devices to be used for replacing the data storage devices;

wherein two or more of said data storage devices constitute a RAID group;

and when it is determined that the data storage device is to be blocked due to failure, the controller

records instruction data indicating a region of data stored in the spare storage device until the blocked data storage device is recovered; and

executes a failure recovery processing corresponding to a content of failure and a predetermined check processing to the data storage device, by writing the data stored in the region of the spare storage device indicated by the instruction data back to the blocked data storage device, at a time point when the blocked data storage device has recovered.

2. The storage system according to claim 1, wherein the failure is one of the following failures of the data storage device:

(1) start failure;

(2) access failure to storage media;

(3) seek operation failure;

(4) hardware operation failure;

or

(5) interface access failure.

3. The storage system according to claim 1, wherein the failure recovery processing is one or more of the following operations (a1) through (a6) executed by the controller to the data storage device:

(a1) power OFF/ON operation;

(a2) hardware reset operation;

(a3) motor stop and restart operation;

(a4) initialization operation of storage area;

(a5) move operation of the storage area to read section; and

(a6) read/write operation of the storage area.

4. The storage system according to claim 1, wherein the check processing is one of the following processes:

(b1) reading of data of the whole storage area;

(b2) writing of data of the whole storage area;

(b3) reading of data and writing of data of the whole storage area;

(b4) reading of data of a predetermined time to the storage area;

(b5) writing of data of a predetermined time to the storage area;

(b6) writing of data and reading of data of a predetermined time to the storage area;

(b7) writing of data and reading of data of the whole storage area, and comparing of write data and read data;

or

(b8) writing of data and reading of data of a predetermined time to the storage area, and comparing of the write data and the read data.

5. The storage system according to claim 1, wherein

the controller manages a number of times of execution of recovery and check in which the recovery processing and the check processing have been executed for each data storage device.

6. The storage system according to claim 5, wherein

the controller does not execute the recovery processing and check processing if the number of times of execution of recovery and check exceeds a predetermined threshold value.

7. The storage system according to claim 6, wherein

the controller determines the threshold value

based on the presence or absence of redundancy at the time failure occurs;

and

based on a storage time of all stored data of the data storage device where failure has occurred to the spare storage device.

8. The storage system according to claim 7, wherein

if the occurrence of failure is caused by an I/O access from the host computer,

the controller determines a type of the check processing based on a combination of two or more of the following:

presence or absence of redundancy, storage time, or I/O access type, determines a permitted number of times of failure for each failure type by the check processing according to the number of times of execution of recovery and check processing, and if the number of times of occurrence of failure occurred by the check processing is smaller than the permitted number of times of failure, cancels blockage of the blocked data storage device.

9. The storage system according to claim 1, wherein the controller

manages a number of times of execution of recovery and check processing in which the recovery processing and check processing have been executed for each data storage device;

determines a permitted number of times of failure for each failure type by the check processing according to the number of times of execution of recovery and check processing; and

if the number of times of occurrence of failure occurred by the check processing is smaller than the permitted number of times of failure, cancels the blockage of the data storage device in the blocked state.

10. The storage system according to claim 1, wherein

when the data storage device where failure has occurred has been recovered by the failure recovery processing and check processing, the controller

switches a storage destination of the data from the spare storage device to the recovered data storage device.

11. The storage system according to claim 1, wherein

when a data update request occurs from the host computer to the data storage device or the spare storage device constituting the RAID group during execution of the recovery processing or the check processing, the controller

stores a data update range to the memory or the data storage device;

and

stores the data in the data update range to the data storage device having the blocked state cancelled.

12. A failure recovery method of a storage device, comprising:

storing data from a host computer to a data storage device, and constituting a RAID group by two or more said data storage devices;

wherein when it is determined that the data storage device is to be blocked due to failure, the method further comprises

recording instruction data indicating a region of data stored in the spare storage device until the blocked data storage device is recovered; and

executing a failure recovery processing corresponding to a content of failure and a predetermined check processing to the data storage device, by writing the data stored in the region of the spare storage device indicated by the instruction data back to the blocked data storage device, at a time point when the blocked data storage device has recovered.

13. The failure recovery method of a storage device according to claim 12, wherein

the failure recovery processing selects and executes one or more of the following operations:

(a1) power OFF/ON;

(a2) hardware reset;

(a3) motor stop and restart;

(a4) initialization of storage area;

(a5) moving of the storage area to read section; and

(a6) reading/writing of the storage area; and

the check processing selects and executes one of the following processes;

(b1) reading of data of the whole storage area;

(b2) writing of data of the whole storage area;

(b3) reading of data and writing of data of the whole storage area;

(b4) reading of data of a predetermined time to the storage area;

(b5) writing of data of a predetermined time to the storage area;

(b6) writing of data and reading of data of a predetermined time to the storage area;

(b7) writing of data and reading of data of the whole storage area, and comparing of write data and read data;

or

(b8) writing of data and reading of data of a predetermined time to the storage area, and comparing of the write data and the read data.

14. A storage system coupled to a host computer and a maintenance terminal, the storage system comprising:

a controller;

a memory;

a plurality of data storage devices for storing data sent from the host computer; and

one or more spare storage devices to be used for replacing the data storage devices;

wherein two or more of said data storage devices constitute a RAID group;

and when it is determined that a data storage device is to be blocked due to failure, the controller

records instruction data indicating a region of data stored in the spare storage device until the blocked data storage device is recovered; and

executes a failure recovery processing corresponding to a content of failure and a predetermined check processing to the data storage device, by writing the data stored in the region of the spare storage device indicated by the instruction data back to the blocked data storage device, at a time point when the blocked data storage device has recovered;

wherein the failure recovery processing is one or more of the following operations executed by the controller;

(a1) power OFF/ON;

(a2) hardware reset;

(a3) motor stop and restart;

(a4) initialization of storage area;

(a5) move of the storage area to read section; and

(a6) reading/writing of the storage area;

wherein the check processing is one of the following processes;

(b1) reading of data of the whole storage area;

(b2) writing of data of the whole storage area;

(b3) reading of data and writing of data of the whole storage area;

(b4) reading of data of a predetermined time to the storage area;

(b5) writing of data of a predetermined time to the storage area;

(b6) writing of data and reading of data of a predetermined time to the storage area;

(b7) writing of data and reading of data of the whole storage area, and comparing of write data and read data;

or

(b8) writing of data and reading of data of a predetermined time to the storage area, and comparing of the write data and the read data;

wherein the controller

stores a number of times of execution of recovery and check in which the failure recovery processing and the check processing have been executed for each data storage device in the memory;

determines a threshold value based on the presence or absence of redundancy at the time failure occurs, and based on a storage time of all stored data of the data storage device where failure has occurred to the spare storage device;

does not execute the failure recovery processing and check processing if the number of times of execution of recovery and check exceeds the threshold value;

determines a type of the check processing based on a combination of two or more of the following;

presence or absence of redundancy, storage time, or I/O access type;

determines a permitted number of times of failure for each failure type by the check processing according to the number of times of execution of recovery and check processing;

if the number of times of occurrence of failure occurred by the check processing is smaller than the permitted number of times of failure, cancels the blockage of the data storage device in the blocked state; and

when the data storage device where failure has occurred has been recovered by the failure recovery processing and check processing, the controller

switches a storage destination of the regenerated data from the spare storage device to the recovered data storage device.