Disk subsystem

• US 8,949,503 B2
• Filed: 09/06/2013
• Issued: 02/03/2015
• Est. Priority Date: 02/02/1999
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Aruga, Kazuhisa
• Primary Examiner(s): PORTKA, GARY J
• Application Number:
  US14/019,588
• Publication Number:
  US 20140006680A1
• Time in Patent Office: 515 Days
• Field of Search: None
• US Class Current: 710/316
• CPC Class Codes: G06F 13/4022 using switching circuits, e.g. switching matrix, connection or expansion network G06F13/4009 takes precedence
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0655 Vertical data movement, i.e. input-output transfer; data movement between one or more hosts and one or more storage devices
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A protocol controller disposed between switches in a fiber channel fabric switch circuit and disk drive units for converting a protocol to enable one-to-one connectivity established between controllers and disk drive units.

Claims

1. A storage system coupled to a plurality of disk drives by at least one of first paths, respectively, comprising:

a plurality of disk controllers coupled to a network for receiving data from an information unit coupled to said network, said plurality of disk controllers implementing Redundant Array of Independent Disks (RAID) processes on said plurality of disk drives; and

a switch coupled to each of said disk controllers by at least one of second paths, respectively,

wherein said switch is further coupled to each of said disk drives by one of said first paths, respectively, thereby forming a point-to-point connection between said each of said disk controllers and said each of said disk drives through said switch,

wherein the number of said second paths is less than the number of said first paths,

wherein said plurality disk drives store data sent from said information unit through said switch, and each of said plurality of disk drives is recognized by an identification (ID) number, and

wherein said switch stores information of said ID numbers and conducts switching between said first and said second paths by transferring data to at least one disk drive among said plurality of disk drives by at least one of said first paths based on said information of said ID number of said at least one disk drive.

2. The storage system according to claim 1,

wherein said switch further includes a protocol converter which converts a protocol of data between said plurality of disk controllers and said plurality disk drives.

3. The storage system according to claim 2,

wherein said storage system has a plurality of said switches, said plurality of switches are coupled to said plurality of disk controllers by said second paths.

4. The storage system according to claim 2,

wherein said switch dynamically switches between said plurality of disk drives.

5. The storage system according to claim 2,

wherein each of said disk controllers generates parity data from data sent from said information unit, and

wherein at least one of said plurality of disk drives stores said parity data.

6. The storage system according to claim 2,

wherein each of said disk controllers generates parity data from data sent from said information unit, and

wherein some disk drives of said plurality of disk drives store data without said parity data.

7. The storage system according to claim 2,

wherein at least one of said plurality of disk drives is a spare disk drive, said spare disk drive storing data from another disk drive of said plurality of disk drives.

8. The storage system according to claim 2,

wherein a first one of said plurality of disk drives is capable of communicating with said switch independently of a first path associated with a second one of said plurality of disk drives.

9. The storage system according to claim 2,

wherein said second paths are fibre channel interface paths.

10. A switch coupled to a plurality of disk drives by at least one of first paths, respectively, and a plurality of disk controllers by at least one of second paths, respectively,

wherein connections between said plurality of disk controllers and said plurality of disk drives are formed as point-to-point connections through the switch by using the first paths and the second paths;

wherein said plurality of disk controllers implement Redundant Array of Independent Disks (RAID) processes on said plurality of disk drives;

wherein each disk drive is recognized by an identification (ID) number; and

wherein said switch stores information of said ID numbers and conducts switching between said first and second paths by transferring data to at least one disk drive of said plurality of disk drives by at least one of said first paths based on said information of said ID number of said at least one disk drive.

11. The switch according to claim 10,

wherein said switch further includes a protocol converter which converts a protocol of data between said plurality of disk controllers and said plurality disk drives.

12. The switch according to claim 11,

wherein said switch dynamically switches between said plurality of disk drives.

13. The switch according to claim 11,

wherein each of said disk controllers generates parity data from data sent from a host computer, and

wherein at least one of said plurality of disk drives stores said parity data.

14. The switch according to claim 11,

wherein each of said disk controllers generates parity data from data sent from a host computer, and

wherein some disk drives of said plurality of disk drives stores data without said parity data.

15. The switch according to claim 11,

wherein at least one of said plurality of disk drives is a spare disk drive, said spare disk drive storing data from another disk drive of said plurality of disk drives.

16. The switch according to claim 11,

wherein a first one of said plurality of disk drives is capable of communicating with said switch independently of a first path associated with a second one of said plurality of disk drives.

17. The switch according to claim 11,

wherein said second paths are fibre channel interface paths.