Patent ID: 8255637
Filing Date: 2012-08-28
Classification: G06F

Abstract:
1. A method of operating a mass storage system comprising a storage layer operatively coupled to a plurality of disk drives constituting a storage space, the method comprising: a. generating one or more consistency checkpoints; b. associating each generated consistency checkpoint with a global number of snapshots generated in the storage system corresponding to time of generation of respective checkpoint; c. upon generating, placing each consistency checkpoint at the beginning of a sequence of dirty data portions which are handled in a cache memory with the help of a replacement technique with an access-based promotion; d. enabling within the sequence of dirty data portions an invariable order of consistency checkpoints and dirty data portions corresponding to volumes with generated snapshots; and e. responsive to destaging a certain consistency checkpoint, recording associated with said certain checkpoint global number of generated snapshots to a predefined storage location configured to be read during a recovery of the storage system.