Patent ID: 9514002
Filing Date: 2016-12-06
CPC Classification: G06F

Claim Text:
1. A method for generating incremental backups for a virtual disk associated with a virtual machine, the method comprising: receiving a first request to take a snapshot of a current virtual disk at a first point in time when the current virtual disk is a first virtual disk, wherein the first virtual disk comprises a first plurality of data blocks and a first block allocation map having a first plurality of entries associated with the first plurality of data blocks; responsive to the first request, generating a second virtual disk comprising a reference to the first virtual disk and a second block allocation map having a second plurality of entries corresponding to the first plurality of entries, and designating the first virtual disk as the snapshot and the second virtual disk as the current virtual disk; storing a copy of the first plurality of data blocks in a second storage device; modifying an indication associated with the first virtual disk, wherein the indication represents that the first virtual disk has been retired; receiving a second request to take a snapshot of the current virtual disk at a second point in time when the current virtual disk is the second virtual disk; responsive to the second request, generating a third virtual disk comprising a reference to the second virtual disk and a third block allocation map having a third plurality of entries corresponding to the second plurality of entries, and designating the second virtual disk as the snapshot and the third virtual disk as the current virtual disk; determining changes to the first plurality of data blocks by examining the second block allocation map; and updating the copy of the first plurality of data blocks in the second storage device based on the determined changes.