Patent ID: 6651075
Filing Date: 2003-11-18
Classification: G06F,Y10S

Abstract:
A computer-readable medium having computer-executable instructions, comprising:retaining a plurality of ordered snapshots associated with a base volume, wherein each snapshot includes an associated differential file; and providing access to a region of a selected snapshot in the plurality of ordered snapshots, by determining whether data associated with at least part of the region exists in the differential file associated with the selected snapshot; if the data exists in the differential file associated with the selected snapshot, associating the data with the at least part of the region; and if the data does not exist in the differential file associated with the selected snapshot, determining if the data exists in a second differential file associated with a second snapshot in the plurality of ordered snapshots, wherein the second snapshot is later than the selected snapshot; and if the data exists in the second differential file associated with the second snapshot, associating the data with the at least part of the region.