Disk array system and method for controlling disk array system

• US 20050120263A1
• Filed: 12/30/2004
• Published: 06/02/2005
• Est. Priority Date: 11/28/2003
• Status: Active Grant

• Current Assignee: Azuma Kano, Ikuya Yagisawa, Takuji Ogawa
• Original Assignee: Azuma Kano, Ikuya Yagisawa, Takuji Ogawa
• Inventors: Ogawa, Takuji, Yagisawa, Ikuya, Kano, Azuma
• Granted Patent: US 7,453,774 B2
• Time in Patent Office: Days
• US Class Current: 714/6
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 3/0614 Improving the reliability of storage systems
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: G11B 20/18 Error detection or correction; Testing , e.g. of drop-outs

Abstract

A disk array system having first and second housings and a controller for controlling the first and second housings. Fiber channel hard disk drives are received in the first housing, and serial ATA hard disk drives are received in the second housing. When reading data stored in a serial ATA hard disk drive in the second housing, the controller reads a plurality of pieces of data including the data to be read and parity data for the plurality of pieces of data from all the hard disk drives of an RAID group to which the hard disk drive storing the data to be read belongs. Thus, the controller examines whether the plurality of pieces of data including the data to be read are written in the hard disk drives with erroneous contents or not.

Claims

1. A storage system, comprising:

a controller controlling to write data to a plurality of storage regions and to read data from said storage regions; and

a plurality of disk drives coupled to said controller having said storage regions,

wherein said controller implements an integrity check of some objects to check and, in case of receiving a read request, processes said read request if said integrity check was implemented at a object concerning to said read request among said objects and implements said integrity check of said object if said integrity check was not implemented at said object.

2. A storage system according to claim 1, wherein said objects are data stored in said storage regions or some heads in said disk drives.

3. A storage system according to claim 1, further comprising:

first data stored in said storage regions being checked to data in the false state by said integrity check,

wherein said first data in said false state are data which are in an address specified for new data by said controller and are not written by said new data, and

wherein said new data are written to an another address which is differ from said address specified for said new data.

4. A storage system according to claim 1, further comprising:

first data stored in said storage regions being checked to data in the false state by said integrity check,

wherein said first data in said false state are data of another contents which are differ from contents specified by said controller.

5. A storage system according to claim 1, wherein said integrity check has a first parity check by using a plurality of first data and a first parity data of said plurality of first data read from some of said disk drives.

6. A storage system according to claim 1, wherein said integrity check has a check whether a head in one of said disk drives is normal or abnormal by comparing contents corresponding to data written to predetermined region in said one of said disk drives and data read from said predetermined region, said contents are stored in said controller until said comparing at the earliest.

7. A storage system according to claim 1, wherein said integrity check has a first parity check by using a plurality of first data and a first parity data of said plurality of first data read from some of said disk drives, and

wherein a check whether a head in one of said disk drives is normal or abnormal by comparing contents corresponding to data written to predetermined region in said one of said disk drives and data read from said predetermined region, said contents are stored in said controller until said comparing at the earliest.

8. A storage system according to claim 1, wherein said integrity check has a first parity check by using a plurality of first data and a first parity data of said plurality of first data read from some of said disk drives, and

wherein said controller does not transfer second data stored in said storage regions to an information unit, said information unit coupled to said controller and transferring a read request or a write request to said controller, if said second data stored in said storage regions are checked to data in said false state by said first parity check.

9. A storage system according to claim 1, wherein said integrity check has a first parity check by using a plurality of first data and a first parity data of said plurality of first data read from some of said disk drives, and

wherein said controller implements second parity checks to one of said plurality of first data, another data and a second parity data read from one or more of said disk drives, said second parity data corresponding to said one of said plurality of first data and said another.

10. A storage system according to claim 1, wherein said integrity check has a check whether a head in one of said disk drives is normal or abnormal by comparing contents corresponding to data written to predetermined region in said one of said disk drives and data read from said predetermined region, said contents are stored in said controller until said comparing at the earliest, and

wherein said controller notices to an information unit, said information unit coupled to said controller and transferring a read request or a write request to said controller, that first data stored in one of said disk drives which has an abnormal head are in the false state or does not transfer said first data to said information unit if said first data are checked in said false state by said integrity check.

11. A storage system according to claim 1, wherein said controller stores a result of said integrity check at an object which is implemented by said controller in said controller.