Patent ID: 7653669
Filing Date: 2010-01-26
Classification: G06F,Y10S

Abstract:
1. A computer readable storage device having instructions encoded thereon for enabling a processor of a host to implement a method that maintains multiple snapshot versions and an active file system, comprising: (a) maintaining an index table that contains an entry for each snapshot and the active file system, wherein the index table entry includes one or more attributes selected from a group of attributes comprising a version number, an image state, a time stamp, a root block pointer, and an image name; (b) maintaining a space map block entry (b, e), wherein b and e represent index table entries, b indicates a first snapshot that uses a first block, and a indicates a last snapshot that uses the first black; (c) allocating a second block; (d) writing data in the second block; and (e) updating any other blocks that pointed to the first block to point to the second block.