System and method for backing up data stored in multiple mirrors on a mass storage subsystem under control of a backup server

• US 6,360,330 B1
• Filed: 03/31/1998
• Issued: 03/19/2002
• Est. Priority Date: 03/31/1998
• Status: Expired due to Term

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Pillai, Ananthan, Shekhar, Ajay, Mutalik, Madhav, Deshayes, John, Merlet, Benoit J., Senie, Faith M.
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Backer, Firmin
• Application Number:
  US09/052,318
• Time in Patent Office: 1,449 Days
• Field of Search: 714/4, 714/6, 714/13, 709/200, 707/205, 707/10, 707/42, 707/3, 707/200, 700/94
• US Class Current: 714/4.1
• CPC Class Codes: G06F 11/1466 to make the backup process non-disruptive
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A backup server controls the backing up of data stored on a mass storage subsystem in response to a backup request from a host identifying data to be backed up during a backup operation, the mass storage subsystem storing data in a plurality of mirrored copies. The backup server comprises a discovery module, a preparation module, an execution module and a clean-up module. The discovery module receives the backup request and identifies, during a discovery phase, at least one storage location on the mass storage subsystem on which data to be backed up during the backup operation is stored. The preparation module, during a preparation phase following the discovery phase, enables the mass storage subsystem to sever one of said mirrored copies and make it available to backup server for the backup operation. In addition, prior to enabling the mass storage subsystem to sever one of the mirrored copies, the preparation module will notify the host, which will stop operating in connection with the data from the mass storage subsystem, and after the mirrored copy has been severed, the preparation module will so notify the host so that it can resume operating in connection with data from at least one of the other copies. The execution module, during the execution phase, enables the mass storage subsystem to retrieve data from the at least one storage location and transfer the retrieved data to the backup server to facilitate backup storage. The clean-up module, during a clean-up phase following the execution phase, verifies that the data to be backed up has been stored in backup storage and enable the mass storage subsystem to re-synchronize the mirrored copies. The backup server also performs a restore operation in response to a restore request from the host.

Claims

1. A backup server for controlling the backing up of data stored on a mass storage subsystem in response to a backup request from a host identifying data to be backed up during a backup operation, the mass storage subsystem storing data in a plurality of mirrored copies, the backup server comprising:

A. a discovery module configured to receive the backup request and identify during a discovery phase at least one storage location on the mass storage subsystem on which data to be backed up during the backup operation is stored;

B. a preparation module configured to, during a preparation phase after the discovery phase, disable the host from operating in connection with data stored on the mass storage subsystem, enable the mass storage subsystem to sever one of said mirrored copies for use during the backup operation and thereafter re-enable the host to operate in connection with data from at least one other of the mirrored copies;

C. an execution module configured to, during the execution phase, enable the mass storage subsystem to retrieve data from the at least one storage location on the severed mirrored copy and transfer the retrieved data to the backup server to facilitate backup storage; and

D. a clean-up module configured to, during a clean-up phase following the execution phase, verify that the data to be backed up has been stored in backup storage and, if so, enable the mass storage subsystem to re-synchronize the mirrored copies.

2. A backup server as defined in claim 1 in which

A. the backup server provides a disable notification during the preparation phase to disable the host to operate in connection with data from at least one other of the mirrored copies, and

B. the host, in response to the disable notification from the backup server, enters a backup mode, in which it stops operations in connection with data stored on the mass storage subsystem.

3. A backup server as defined in claim 2 in which

A. the backup server provides an enable notification during the preparation phase to re-enable the host to operate in connection with data from at least one other of the mirrored copies, and

B. the host, in response to the enable notification from the backup server, resumes operations in connection with data stored on the mass storage subsystem.

4. A backup server as defined in claim 1 further including a backup data store interface configured to transfer data provided by the mass storage subsystem to a backup data store for storage.

5. A backup server as defined in claim 1 in which the backup request includes a file identification identifying at least one file and in which the host includes a file system, the discovery module querying the file system to receive the identification of the at last one storage location.

6. A backup server as defined in claim 5 in which the mass storage subsystem includes at least one logical volume on which data is stored, the file system providing an identification of the logical volume the identification of the at least one storage location.

7. A backup server as defined in claim 6 in which the mass storage subsystem includes at least one physical storage device, the logical volume including at least a portion of the physical storage device, and the data comprising the file being stored on at least one portion of the at least one physical storage device, the host further including a logical volume manager, the discovery module querying the logical volume manager to obtain an identification of the at least one portion of the at least one physical storage device on which data comprising the file is stored.

8. A backup server as defined in claim 7 in which the physical storage device stores data on a series of blocks, identification of the at least one portion of the at least one physical storage device including a base block identifier identifying at least one of said blocks and a length value identifying a number of contiguous blocks comprising said at least one portion of he at least one physical storage device.

9. A backup server as defined in claim 1 in which the backup server further maintains a catalog for backed-up data, the clean-up module further begin configured to update the catalog during the clean-up phase to identify a location of the data backed up during the backup operation on a backup storage medium.

10. A backup server for controlling the restoration of data on a mass storage subsystem in response to a restore request from a host identifying data to be restored during a restore operation, the mass storage subsystem storing data in a plurality of mirrored copies, the backup server comprising:

A. a discovery module configured to receive the restore request and identify during a discovery phase at least one storage location on the mass storage subsystem on which data to be restored during the backup operation;

B. a preparation module configured to, during a preparation phase after the discovery phase, enable the mass storage subsystem to sever one of said mirrored copies for use during the backup operation;

C. an execution module configured to, during the execution phase, enable the mass storage subsystem to receive data from backup storage and store it on the at least one storage location on the severed mirrored copy to facilitate restoration; and

D. a clean-up module configured to, during a clean-up phase following the execution phase, verify that the data to be restored has been stored on the at least one storage location and, if so, enable the mass storage subsystem to re-synchronize the mirrored copies.

11. A backup server as defined in claim 10 in which the which the backup server provides a disable notification during the preparation phase to disable the host to operate in connection with data from at least one other of the mirrored copies.

12. A backup server as defined in claim 11 in which the backup server provides an enable notification during the preparation phase to re-enable the host to operate in connection with data from at least one other of the mirrored copies.

13. A backup server as defined in claim 10 further including a backup data store interface configured to receive from a backup data store for transfer to the mass storage subsystem.

14. A backup server as defined in claim 10 in which the restore request includes a file identification identifying at least one file and in which the host includes a file system, the discovery module querying the file system to receive the identification of the at last one storage location.

15. A backup server as defined in claim 14 in which the mass storage subsystem includes at least one logical volume on which data is stored, the file system providing an identification of the logical volume as the identification of the at least one storage location.

16. A backup server as defined in claim 15 in which the mass storage subsystem includes at least one physical storage device, the logical volume including at least a portion of the physical storage device, and the data comprising the file being stored on at least one portion of the at least one physical storage device, the host further including a logical volume manager, the discovery module querying the logical volume manager to obtain an identification of the at least one portion of the at least one physical storage device on which data comprising the file is stored.

17. A backup server as defined in claim 16 in which the physical storage device stores data on a series of blocks, identification of the at least one portion of the at least one physical storage device including a base block identifier identifying at least one of said blocks and a length value identifying a number of contiguous blocks comprising said at least one portion of he at least one physical storage device.

18. A backup server as defined in claim 10 in which the backup server further maintains a catalog for backed-up data, the clean-up module further begin configured to update the catalog during the clean-up phase to identify a location of the data backed up during the backup operation on a backup storage medium.

19. A method of operating a backup arrangement including a backup server for controlling the backing up of data stored on a mass storage subsystem in response to a backup request from a host identifying data to be backed up during a backup operation, the mass storage subsystem storing data in a plurality of mirrored copies, the method comprising the steps of:

A. enabling the backup server to receive the backup request and identify during a discovery phase at least one storage location on the mass storage subsystem on which data to be backed up during the backup operation is stored;

B. enabling the backup server to, during a preparation phase after the discovery phase, disable the host from operating in connection with data stored on the mass storage subsystem, enable the mass storage subsystem to sever one of said mirrored copies for use during the backup operation and thereafter re-enable the host to operate in connection with data from at least one other of the mirrored copies;

C. enabling the backup server to, during the execution phase, enable the mass storage subsystem to retrieve data from the at least one storage location on the severed mirrored copy and transfer the retrieved data to the backup server to facilitate backup storage; and

D. enabling the backup server to, during a clean-up phase following the execution phase, verify that the data to be backed up has been stored in backup storage and, if so, enable the mass storage subsystem to re-synchronize the mirrored copies.

20. A method of operating a backup arrangement including a backup server for controlling the restoration of data on a mass storage subsystem in response to a restore request from a host identifying data to be restored during a restore operation, the method comprising the steps of:

A. enabling the backup server to receive the restore request and identify during a discovery phase at least one storage location on the mass storage subsystem on which data to be restored during the backup operation;

B. enabling the backup server to, during a preparation phase after the discovery phase, enable the mass storage subsystem to sever one of said mirrored copies for use during the backup operation;

C. enabling the backup server to, during the execution phase, enable the mass storage subsystem to receive data from backup storage and store it on the at least one storage location on the severed mirrored copy to facilitate restoration; and

D. enabling the backup server to, during a clean-up phase following the execution phase, verify that the data to be restored has been stored on the at least one storage location and, if so, enable the mass storage subsystem to re-synchronize the mirrored copies.

21. A computer program product for use in connection with a computer to form a backup server for controlling the backing up of data stored on a mass storage subsystem in response to a backup request from a host identifying data to be backed up during a backup operation, the computer program product including a computer-readable medium having encoded thereon:

A. a discovery module configured to enable the computer to receive the backup request and identify during a discovery phase at least one storage location on the mass storage subsystem on which data to be backed up during the backup operation is stored;

B. a preparation module configured to enable the computer to, during a preparation phase after the discovery phase, disable the host from operating in connection with data stored on the mass storage subsystem, enable the mass storage subsystem to sever one of said mirrored copies for use during the backup operation and thereafter re-enable the host to operate in connection with data from at least one other of the mirrored copies;

C. an execution module configured to enable the computer to, during the execution phase, enable the mass storage subsystem to retrieve data from the at least one storage location on the severed mirrored copy and transfer the retrieved data to the backup server to facilitate backup storage; and

D. a clean-up module configured to enable the computer to, during a clean-up phase following the execution phase, verify that the data to be backed up has been stored in backup storage and, if so, enable the mass storage subsystem to re-synchronize the mirrored copies.

22. A computer program product for use in connection with a computer to form a backup server for controlling the restoration of data on a mass storage subsystem in response to a restore request from a host identifying data to be restored during a restore operation, the computer program product including a computer-readable medium having encoded thereon:

A. a discovery module configured to enable the computer to receive the restore request and identify during a discovery phase at least one storage location on the mass storage subsystem on which data to be restored during the backup operation;

B. a preparation module configured to enable the computer to, during a preparation phase after the discovery phase, enable the mass storage subsystem to sever one of said mirrored copies for use during the backup operation;

C. an execution module configured to enable the computer to, during the execution phase, enable the mass storage subsystem to receive data from backup storage and store it on the at least one storage location on the severed mirrored copy to facilitate restoration; and

D. a clean-up module configured to enable the computer to, during a clean-up phase following the execution phase, verify that the data to be restored has been stored on the at least one storage location and, if so, enable the mass storage subsystem to re-synchronize the mirrored copies.