Disk array controller

• US 20040111560A1
• Filed: 08/12/2003
• Published: 06/10/2004
• Est. Priority Date: 12/10/2002
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Fujimoto, Kazuhisa, Takase, Masayuki
• Granted Patent: US 7,120,740 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

Disclosed herewith is a disk array system configured by a plurality of disk array controllers and another disk array apparatus that are operated as an integrated storage system while the system is prevented from degradation of the performance. The disk array controller is provided with a channel interface unit, a disk interface unit, a cache memory unit, a shared memory unit, a shared memory interconnection network for connecting a plurality of disk array control units to each another, and an inter-unit CM-SW for connecting a plurality of disk array control units to each another. The shared memory unit includes another disk array apparatus volume information collection unit for retaining volume information of another disk array apparatus while the inter-unit CM-SW includes a protocol translation interface.

Claims

1. A disk array controller, comprising:

at least one disk array control unit connected to a host computer or disk drive; and

a switch A connected to another disk array apparatus that is different from said disk array control unit and said disk array control unit;

wherein said disk array control unit includes;

an external device connection interface unit connected to said host computer or disk drive;

a cache memory unit for storing data read/written from/to said disk drive or another disk array apparatus;

a shared memory unit for storing control information of the connection between said external device connection interface unit and said cache memory unit and management information of said disk drive;

a switch B connected to said external device connection interface unit and said cache memory unit, as well as to said switch A;

a switch C connected to said external device connection interface unit and said shared memory unit; and

a protocol processing unit for processing commands addressed to an external volume control unit that stores volume information of another disk array unit and said disk drive;

wherein said switch A includes;

an internal interface corresponding to a protocol A used for the communication in said disk array unit; and

a protocol translation interface for translating a protocol B used in said different disk array unit into said protocol A.

3. The disk array controller according to claim 1,

wherein at least said one disk array unit or another disk array apparatus is connected to said switch A through a star-type network.

4. The disk array controller according to claim 1,

wherein said external volume control unit is disposed in said shared memory unit.

5. The disk array controller according to claim 1,

wherein said protocol processing unit is disposed in said external device connection interface unit.

6. The disk array controller according to claim 1,

wherein said disk array controller includes an external cache space for storing data read/written from/to another disk array apparatus temporarily.

7. The disk array controller according to claim 6,

wherein said external cache space is provided in said cache memory unit.

8. The disk array controller according to claim 1,

wherein said switch A includes a plurality of internal interfaces and a plurality of protocol translation interfaces.

9. The disk array controller according to claim 1,

wherein said disk array controller includes a management console terminal provided with a screen for displaying volume information of another disk array apparatus.

2. A disk array controller, comprising:

at least one disk array control unit connected to a host computer or disk drive; and

an inter-unit cache memory switch connected to a disk array apparatus that is different in type from said disk array control unit, as well as to said disk array control unit;

wherein said disk array control unit includes;

an external device connection interface unit connected to said host computer or disk drive;

a cache memory unit for storing data read/written from/to said disk drive or another disk array apparatus;

a shared memory unit for storing control information of the connection between said external device connection interface unit and said cache memory unit, as well as management information of said disk drive;

a cache memory switch connected to said external device connection interface unit and said cache memory unit, as well as to said inter-unit cache memory switch;

a shared memory switch connected to said external device connection interface unit and said shared memory unit;

a protocol processing unit for processing commands addressed to an external volume control unit that stores volume information of another disk array unit and said different disk drive;

wherein said inter-unit cache memory switch includes;

an internal interface corresponding to a communication internal protocol used in said disk array control unit; and

a protocol translation interface for translating a standard protocol used for communications in said disk array control unit into said internal protocol.

10. A disk array controller, comprising:

a first disk array control unit;

a second disk array control unit; and

a switch for connecting said first disk array unit to said second disk array control unit;

wherein each of said first and second disk array control units includes;

an external device connection interface unit connected to a host computer or hard disk drive;

a cache memory unit;

a shared memory unit; and

a cache memory switch connected to said cache memory unit to said external device connection interface unit;

wherein said switch includes;

a first interface connected to said first or second disk control unit;

a third interface connected to another disk array apparatus that uses a communication protocol different from that used for said first and second disk control units; and

means for translating said communication protocol used in both of said first and second disk control units into a communication protocol used in another disk array apparatus;

wherein at least one of said first and second disk array control units includes means for storing volume information of another disk array apparatus.

11. A method for controlling a disk array controller provided with a plurality of disk array control unit, each having an interface with a host computer, a cache memory, and a shared memory;

an inter-unit memory switch connected among cache memories of said plurality of disk array control units; and

another disk array apparatus connected to said inter-unit cache memory switch,

wherein said method comprises;

receiving a data read request from said host computer;

determining a cache memory that stores data requested with said read request;

sending a data read request to another disk array apparatus; and

translating the communication protocol used for said read request into a standard protocol.