FILE SYSTEM MIGRATION

• US 20130054520A1
• Filed: 05/13/2010
• Published: 02/28/2013
• Est. Priority Date: 05/13/2010
• Status: Active Grant

• Current Assignee: Valtrus Innovations Limited (f/k/a Dolya Holdco 9 Limited) (Key Patent Innovations Limited)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Sampathkumar, Kishore Kaniyar
• Granted Patent: US 9,037,538 B2
• Time in Patent Office: Days
• US Class Current: 707/610
• CPC Class Codes: G06F 16/119 Details of migration of file systems migration mechanisms in storage systems G06F3/0647
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

A method to perform file system migration is described. The method comprises associating a source block device to a destination block device, wherein the source block device and the destination block device include a plurality of source blocks and destination blocks, respectively. At least one command for a source block from the plurality of source blocks is directed to the source block device or the destination block device based at least on the associating. Further, a destination block from the plurality of destination blocks is updated based, in part, on the at least one directed command.

Claims

1. A method to perform file system migration, the method comprising:

associating a source block device to a destination block device, wherein the source block device and the destination block device include a plurality of source blocks and destination blocks, respectively;

directing at least one command for a source block from the plurality of source blocks to the source block device or the destination block device based at least on the associating; and

updating a destination block from the plurality of destination blocks based, in part, on the at least one directed command.

2. The method as claimed in claim 1, wherein the at least one command is generated during the file system migration.

3. The method as claimed in claim 1, wherein the directing the at least one command further comprises subsequently directing the at least one command to the destination block associated with the source block when the at least one command is a write request.

4. The method as claimed in claim 1, wherein the directing further comprises:

for the at least one command being a read request, subsequently directing the at least one command to the source block, if a corresponding destination block has not been updated; and

for the at least one command being the read request, subsequently directing the at least one command to another destination block from the plurality of destination blocks corresponding to the source block, if the another destination block has been updated.

5. The method as claimed in claim 1, further comprises copying the plurality of the source blocks, associated with the plurality of destination blocks that have not been updated, to the destination block device.

6. A computing device comprising:

a processor;

a memory coupled to the processor, wherein the memory comprises;

an association module configured to associate a source block device with a destination block device; and

a migration module configured to,

determine whether at least one block on the destination block device, associated with at least one block on the source block device, is updated on the destination block device; and

migrate a file system on the source block device to the destination block device based on the determination.

7. The computing device as claimed in claim 6, wherein the migration module is further configured to modify a file system update bitmap to track updates to the at least one block on the destination block device.

8. The computing device as claimed in claim 7, wherein the migration module is further configured to modify the file system update bitmap when the at least one block on the destination block device is updated.

9. The computing device as claimed in claim 6, wherein the migration module is further configured to compute a copy bitmap indicating the at least one block on the source block device that has not been updated at the destination block device.

10. The computing device as claimed in claim 9, wherein the migration module is further configured to migrate the file system based on the copy bitmap.

11. A computer-readable medium having a set of computer readable instructions that, when executed, perform acts comprising:

in response to at least one command for relocation of at least one block on the source block device, relocating the block from a source block device to a destination block device based on an association between the source block device and the destination block device; and

updating a file system update bitmap associated with the source block device in response to the relocating;

copying at least one other block from the source block device to the destination block device based on the updating, wherein the other block has not been relocated.

12. The computer-readable medium as claimed in claim 11, wherein the copying further includes computing a copy bitmap based on the file system update bitmap and a destination allocation bitmap.

13. The computer readable medium as claimed in claim 11, wherein the copying is based on a source allocation bitmap when none of the blocks of the source block device are updated.

14. The computer readable medium as claimed in claim 11, wherein the relocating comprises mapping the at least one block of the source block device to at least one block on the destination block device.

15. The computer readable medium as claimed in claim 14, wherein the relocating further comprises directing commands to the at least one source block device for reading at least one block from a source block device based on the mapping, when the at least one block has not been updated at the destination block device.