Host-independent incremental backup method, apparatus, and system
View Patent ↗Block-level operations are tracked within a storage subsystem. Metadata corresponding to the block-level operations are collected within the storage subsystem between snapshot (i.e., backup) instances. The collected metadata are referenced to ensure that only overwritten data blocks are copied to the backup device. The present invention leverages the capabilities of flashcopy operations, frees the host from costly housekeeping tasks, and facilitates efficient backup operations independent of a host or filesystem.
1. A storage controller for controlling storage devices and conducting block-level incremental backups within a storage subsystem in a host-independent manner, the storage controller configured to:
track block-level write operations on a storage volume without communicating with a host that manages the storage controller;
collect metadata describing the block-level write operations;
receive a first snapshot command at a first time instance;
receive a second snapshot command at a second time instance, the first snapshot command and the second snapshot command each referencing the storage volume as the source volume for the snapshot command; and
transfer data corresponding to blocks overwritten on the storage volume between the first time instance and the second time instance to a backup device based on the metadata.
2. The storage controller of claim 1 , wherein the metadata is stored within the storage subsystem.
3. The storage controller of claim 1 , further configured to store the metadata on the backup device.
4. The storage controller of claim 1 , further configured to track block-level write operations by initiating a flashcopy command.
5. The storage controller of claim 1 , wherein the first snapshot command corresponds to a baseline backup.
6. The storage controller of claim 1 , wherein the second snapshot command corresponds to an incremental backup.
7. The storage controller of claim 1 , wherein the first and second snapshot commands are received from the host.
8. The storage controller of claim 1 , wherein the first and second snapshot commands are scheduled events.
9. The storage controller of claim 1 , wherein the backup device is comprises one of a tape device, a magnetic device, an optical device, a solid state device, a tape library, and a second storage subsystem.
10. A storage subsystem for storing data and conducting block-level incremental backups in a host-independent manner, the storage subsystem comprising:
a plurality of storage devices; and
at least one controller configured to track block-level write operations on a storage volume without communicating with a host that manages the at least one controller, collect metadata describing the block-level write operations, receive a first snapshot command at a first time instance, receive a second snapshot command at a second time instance, the first snapshot command and the second snapshot command each referencing the storage volume as the source volume for the snapshot command, and transfer data corresponding to blocks overwritten on the storage volume between the first time instance and the second time instance to a backup device based on the metadata.
11. A system for archiving data in a host-independent manner, the system comprising:
at least one host configured to process data and request storage services;
a plurality of storage devices; and
at least one controller configured to track block-level write operations on a storage volume without communicating with the at least one host that manages the at least one controller, collect metadata describing the block-level write operations, receive a first snapshot command at a first time instance, receive a second snapshot command at a second time instance, the first snapshot command and the second snapshot command each referencing the storage volume as the source volume for the snapshot command and transfer data corresponding to blocks overwritten on the storage volume between the first time instance and the second time instance to a backup device based on the metadata.
12. A storage area network for storing data, the storage area network comprising:
a plurality of storage subsystems;
a network configured to interconnect the plurality of storage subsystems; and
at least one storage subsystem of the plurality of storage subsystems comprising at least one controller configured to track block-level write operations on a storage volume without communicating with a host that manages the at least one storage subsystem, collect metadata describing the block-level write operations, receive a first snapshot command at a first time instance, receive a second snapshot command at a second time instance, the first snapshot command and the second snapshot command each referencing the storage volume as the source volume for the snapshot command, and transfer data corresponding to blocks overwritten on the storage volume between the first time instance and the second time instance to a backup device based on the metadata.
13. A computer readable storage medium comprising computer readable program code for conducting incremental snapshots within a storage subsystem in a host-independant manner, the program code configured to:
track block-level write operations on a storage volume without communicating with a host configured to manage the storage volume;
collect metadata describing the block-level write operations;
receive a second snapshot command at a first time instance;
receive a second snapshot command at a first time instance the first snapshot command and the second snapshot command each referencing the storage volume as the source volume for the snapshot command; and
transfer data corresponding to blocks overwritten on the storage volume between the first time instance and the second time instance to a backup device based on the metadata.
14. An apparatus for conducting block-level incremental backups in a host-independent manner within a storage subsystem, the method comprising:
means for tracking block-level write operations on a storage volume without communicating with a host configured to manage the storage subsystem;
means for collecting metadata describing the block-level write operations;
means for receiving a first snapshot command at a first time instance;
means for receiving a second snapshot command at a second time instance the first snapshot command and the second snapshot command each referencing the storaae volume as the source volume for the snapshot command; and
means for transferring data corresponding to blocks overwritten on the storage volume between the first and second time instance to a backup device based on the metadata.
15. A method for conducting block-level incremental backups in a host-independent manner within a storage subsystem, the method comprising:
tracking block-level write operations on a storage volume without communicating with a host confirmed to manage the storage subsystem;
collecting metadata describing the block-level write operations;
receiving a first snapshot command at a first time instance;
receiving a second snapshot command at a second time instance, the first snapshot command and the second snapshot command each referencing the storage volume as the source volume for the snapshot command; and
transferring data corresponding to blocks overwritten on the storage volume between the first and second time instance to a backup device based on the metadata.
16. The method of claim 15 , wherein the metadata is stored within the storage subsystem.
17. The method of claim 15 , wherein tracking block-level write operations is initiated with a flashcopy command.
18. The method of claim 15 , wherein the first snapshot command corresponds to a baseline backup.
19. The method of claim 15 , wherein the second snapshot command corresponds to an incremental backup.
20. The method of claim 15 , wherein the first and second snapshot commands are received from the host.
21. The method of claim 15 , wherein the first and second snapshot commands are scheduled events conducted within the storage subsystem.
22. The method of claim 15 , wherein the backup device comprises one of a tape device, a magnetic device, an optical device, a solid state device, a tape library, and a second storage subsystem.