System and method for storage system

• US 20030212860A1
• Filed: 02/28/2003
• Published: 11/13/2003
• Est. Priority Date: 03/01/2002
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Jiang, Xiaoming, Yagisawa, Ikuya, Yagi, Satoshi, Mitsutaka, Daisuke
• Granted Patent: US 6,985,997 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0658 Controller construction arrangements
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores

Abstract

In a storage system including a plurality of data controllers that receive a data input/output request that is input via an external communication path and perform data input/output processing with respect to a storage resource in response to this request, the plurality of data controllers being connected by a data communication path and being able to communicate with one another, if a data input/output request has been input into one of the controllers, the plurality of data controllers and shares execution of the data input/output processing by communication through the data communication path.

Claims

1. A storage system having a plurality of data controllers that receive a data input/output request that is input via an external communication path from a host computer and perform data input processing with respect to a storage resource in response to this request, said plurality of data controllers being connected by a data communication path and being able to communicate with one another;

said storage system comprising;

a first data controller that, if a data input request has been received via said external communication path from said host computer, communicates said received data input request via said data communication path to at least one second data controller and writes a portion of the data for which said input request has been received into said storage resource; and

said second data controller that, based on said data input request that has been received from said first controller, performs a writing process with respect to said storage resource for a portion of data for which said input request has been received.

2. The storage system according to claim 1,

wherein said first and second data controllers manage said storage resource by one of the schemes of RAID 3 to 6;

and

when said first data controller has received a data write request as said data input/output request, said first data controller divides the data to be written into writing units in accordance with said one of the schemes of RAID 3 to 6, and performs an assignment process, in which said first data controller assigns said second data controllers that is to handle the writing process to the divided units one by one.

3. The storage system according to claim 2,

wherein a data controller performing parity calculation is selected in said assignment process, and the selected data controller executes said parity calculation.

4. The storage system according to claim 3,

wherein for each stripe that is composed when managing said strage resource with said RAID scheme, a state of the assignment of the data controller handling the parity calculation of the stripe is stored;

and

the data controller handling the stripe to be a writing target executes the parity calculation of the stripe when writing data into said storage resource.

5. The storage system according to claim 4,

wherein said assignment process dynamically changes said data controller in charge of said parity calculation.

6. The storage system according to claim 1,

wherein said plurality of data controllers share execution of a process of writing, into said storage resource, with respect to data that are written as one stripe that is composed when managing said storage resource with a RAID scheme.

7. A storage system having a plurality of data controllers that receive a data input/output request that is input via an external communication path from a host computer and perform data input processing with respect to a storage resource in response to this request, said plurality of data controllers being connected by a data communication path and being able to communicate with one another;

said storage system comprising;

a first data controller that, if a data read request has been accepted via said external communication path from said host computer, communicates said received data read request via said data communication path to at least one second data controller, reads out from said storage resource a portion of the data for which said data read request has been received and sends said read portion of the data to said external communication path; and

said second data controller that, based on said data read request that has been received from said first controller, performs a process of reading out from said storage resource a portion of the data for which said data read request has been received and sends said read portion of the data to said external communication path.

8. The storage system according to claim 7,

wherein said first and second data controllers manage said storage resource by one of the schemes of RAID 3 to 6;

and

wherein, when said first data controller has received a data read request as said data input/output request, said first data controller divides the data to be read out into reading units in accordance with of said one of the schemes of RAID 3 to 6, and performs an assignment process, in which the first data controller assigns said second data controller that is to handle the reading process to the divided units one by one.

9. The storage system according to claim 8,

wherein a process of reading, from said storage resource, data that are read out as one stripe that is composed when managing said storage resource with said RAID scheme is executed after assigning the data controller that is to handle said reading process among said plurality of data controllers.

10. A control method for a storage system having a plurality of data controllers that receive a data input/output request that is input via an external communication path and perform data input/output processing with respect to a storage resource in response to this request, said plurality of data controllers being connected by a data communication path and being able to communicate with one another;

said control method comprising;

a first step, in which a first data controller, which is one of said plurality of data controllers, receives said data input/output request;

a second step, in which said first controller communicates said data input/output request received in the first step to a second data controller other than said first data controller; and

a third step, in which said first controller executes a portion of the received processing of said input/output request with respect to said storage resource, and said second controller executes a portion of the processing of said data input/output request with respect to said storage resource, which said second data controller has received from said first controller.

11. A control method for a storage system having a plurality of data controllers that receive a data input/output request that is input via an external communication path and perform data input/output processing with respect to a storage resource in response to this request, said plurality of data controllers being connected by a data communication path and being able to communicate with one another;

said control method comprising;

a first step, in which, if said data input/output request is a data write request, then a first data controller, which is one of said plurality of data controllers, receives said data write request;

a second step, in which said first controller communicates said data write request received in said first step to a second data controller other than said first controller; and

a third step, in which said first controller executes a portion of the processing of said received data write request with respect to said storage resource, and said second controller executes a portion of the processing of said write request with respect to said storage resource, which said second controller has received from said first controller.

12. A control method for a storage system having a plurality of data controllers that receive a data input/output request that is input via an external communication path and perform data input/output processing with respect to a storage resource in response to this request, said plurality of data controllers being connected by a data communication path and being able to communicate with one another;

said control method comprising;

a first step, in which, if said data input/output request is a data read request, then a first data controller, which is one of said plurality of data controllers, receives said data read request;

a second step, in which said first controller communicates said data read request received in said first step to a second data controller other than said first controller;

a third step, in which said first controller executes a portion of the processing of said received data read request to read the data out of said storage resource, and said second controller executes a portion of the processing of reading request with respect to said storage resource, which said second data controller has received from said first controller;

a fourth step, in which said second controller sends the data that it has read out to said first controller; and

a fifth step, in which said first controller sends the data that it has read out itself and the data that were read out by said second controller and sent therefrom via said external communication path.