Systems and methods for striped storage migration
Systems and methods for expanding capacity of a storage system are provided. Data blocks of a capacity increasing disk are pre-configured with a first progress indicator used to determine correctly migrated data blocks. A migrator migrates groups of data blocks among present disk(s) and capacity increasing disk(s). Each group comprises a predetermined number of data blocks. An updater updates a second progress indicator of the second disk in response to completion of migration of each group. The migrator is adapted to generate the first progress indicator such that it may resume migration of groups of data blocks after a migration interruption according to the first and the second progress indicators.
1. A method of expanding capacity in a storage system, comprising steps of:
configuring data blocks of a first disk with a first progress indicator used to determine correctly migrated data blocks;
migrating groups of data blocks between a second disk and the first disk, wherein each group comprises a predetermined number of data blocks; and
updating a second progress indicator of the first disk in response to completion of migration of each group, wherein an updated said second progress indicator indicates completion of migration of said groups of data blocks and wherein the steps of migrating and updating may resume after a migration interruption according to the first progress indicator and to the second progress indicator.
2. The method of claim 1 , wherein the step of configuring further comprises a step of storing a signature in the data blocks of the first disk.
3. The method of claim 2 , wherein the step of migrating further comprises a step of overwriting the signature when one of the data blocks of the second disk migrates to one of the data blocks of the first disk.
4. The method of claim 1 , wherein the step of resuming further comprises a step of determining from the second progress indicator one of said groups of data blocks wherein the step of migrating last occurred such that the migration may resume.
5. The method of claim 4 , wherein the step of resuming further comprises a step of comparing the first progress indicator to one of the data blocks of the first disk to determine a correcfly migrated data block within said one of said groups of data blocks.
6. The method of claim 1 , wherein the step of updating the second progress indicator further comprises a step of updating a first counter after all of the data blocks of one of said groups of data blocks migrates to the first disk.
7. The method of claim 6 , wherein the step of updating the second progress indicator further comprises a step of updating a second counter to backup the first counter.
8. A storage system, comprising:
a first storage disk having data blocks; and
a second storage disk communicatively connected to the first storage disk and having data blocks, wherein the second storage disk comprises
a first progress indicator configured for determining whether one of the data blocks of the first storage disk has correctly migrated to one of the data blocks of the second storage disk, and
a second progress indicator configured for determining whether a group of the data blocks of the first storage disk has completed migrating to the second storage disk, wherein migration of the data blocks can resume in the event of a migration interruption based on the first and the second progress indicators.
9. A system for expanding capacity in a storage system, comprising:
a migrator communicatively connected to a first disk and to a second disk and configured for migrating groups of data blocks between the first disk and the second disk, wherein each group comprises a predetermined number of data blocks;
a first progress indicator indicative of miaration of data blocks within groups:
a second progress indicator indicative of migration of groups; and
an updater communicatively connected to the migrator and configured for updating the second progress indicator in response to completion of migration of each group, wherein an updated said second progress indicator indicates the completed migration of said groups of data blocks,
wherein the migrator is adapted to update the first progress indicator used to determine correctly migrated data blocks such that the migrator may resume migration of said groups of data blocks after a migration interruption according to the first and the second progress indicators.
10. The system of claim 9 , wherein the migratory further comprises a recovery unit for determining from the second progress indicator one of the groups of the data blocks wherein the migration last occurred such that the migration may resume from that group.
11. The system of claim 9 , further comprising an I/O unit configured for assigning the first progress indicator to data blocks of the second disk, wherein the first progress indicator includes a signature used to determine the correctly migrated data blocks.
12. The disk migration system of claim 11 , wherein the migratory further comprises a comparator configured for comparing the signature to one of the data blocks of the second disk to determine one correctly migrated data block within said one of the groups of the data blocks.
13. The system of claim 9 , wherein the updater further comprises a counter configured for incrementing after all of the data blocks of one of said groups of data blocks migrate to the second disk.
14. The system of claim 13 , wherein the updater further comprises a second counter configured for incrementing after all of the data blocks of one of said groups of data blocks migrates to the second disk as a backup to the first counter.