Distributed snapshot process

• US 20040153615A1
• Filed: 01/20/2004
• Published: 08/05/2004
• Est. Priority Date: 01/21/2003
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Equallogic Incorporated (Dell Technologies Inc.)
• Inventors: Long, Paula, Hayden, Peter C., Koning, G. Paul, Lee, Hsin H.
• Granted Patent: US 7,127,577 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data

Abstract

Systems and methods for providing an efficient partitioned resource server. In one embodiment, the partitioned resource server comprises a plurality of individual servers, and the individual servers support a storage service. The systems and methods provide archiving processes for a partitioned storage service. To this end, the systems and process may include a snapshot process operating on a server and capable of coordinating with other snapshot processes for generating state information representative of the state of the partitioned storage volume.

Claims

1. Systems for providing a partitioned storage service, comprising

at least two servers,

a storage volume partitioned across the at least two servers, and

at least two snapshot processes operating on respective ones of the at least two servers and capable of coordinating with other snapshot processes for generating state information representative of the state of the partitioned storage volume.

2. Systems according to claim 1, wherein

the snapshot process includes a coordinating process for generating commands for coordinating at least one other snapshot process to generate state information representative of the state of the partitioned storage volume.

3. Systems according to claim 2, wherein

the coordinating process includes a time-stamp process for time stamping a command to generate a snapshot process.

4. Systems according to claim 1, wherein

the snapshot process includes a request control process for processing requests received by the respective server.

5. Systems according to claim 4, wherein

the request control process includes a suspend process for suspending processing of requests by the respective server.

6. Systems according to claim 4, wherein

the request control process includes a time-stamp process for time stamping requests received by the respective server.

7. Systems according to claim 1, wherein

the snapshot process includes process for analyzing suspended requests to determine requests received after a selected time.

8. Systems according to claim 1, further including

an archive process for employing the state information to create a copy of the storage volume.

9. Systems according to claim 1, further comprising

a plurality of storage volumes partitioned across the at least two servers.

10. A process for providing a partitioned storage service, comprising the steps of

providing at least two servers and a storage volume partitioned across the at least two servers, and

operating at least two snapshot processes on respective ones of the at least two servers and capable of coordinating with other snapshot processes for generating state information representative of the state of the partitioned storage volume.

11. A process according to claim 10, including

coordinating at least one other snapshot process to generate state information representative of the state of the partitioned storage volume.

12. A process according to claim 11, wherein

coordinating includes time-stamping a command to generate a snapshot process.

13. A process according to claim 10, wherein operating a snapshot process includes

operating a request control process for processing requests received by the respective server.

14. A process according to claim 13, wherein

the request control process includes a suspend process for suspending processing of requests by the respective server.

15. A process according to claim 13, wherein

the request control process time stamps requests received by the respective server.

16. A process according to claim 13, further including

analyzing suspended requests to determine requests received after a selected time.

17. A process for generating a snapshot of a storage volume distributed across at least two servers, comprising

executing snapshot processes on respective ones of the at least two servers,

providing an administration command to a first one of the snapshot processes directing the snapshot processes to generate state information representative of the state of the partitioned storage volume,

having the first snapshot process hold pending requests and direct at least a second snapshot process to hold pending client requests,

having the second snapshot process to indicate that requests have been held, and

having the first snapshot process generate state information representative of the state of a storage partition maintained on its respective server and generate a snapshot command for the second server to generate information representative of the state of a storage partition maintained on its respective server.

18. A process according to claim 17, wherein

the administration command includes a prepare command to a second server supporting the data volume for which a snapshot is being created.

19. A process according to claim 17, further comprising

processing the state information to generate an archive copy of the storage volume.

20. A process according to claim 17, further comprising

having the first and second snapshot processes release pending requests after generating the state information.

21. A storage area network, comprising

a data network having at least two servers,

a storage volume partitioned across the at least two servers, and

at least two snapshot processes operating on respective ones of the at least two servers and capable of coordinating with other snapshot processes for generating state information representative of the state of the partitioned storage volume.