Patent ID: 6101585
Filing Date: 2000-08-08
Classification: G06F,Y10S

Abstract:
A method for enabling accurate incremental backup operations initiated by a backup application for an on-line file of a computer system having an archive bit attribute associated with the file, the method comprising the steps of:creating a snapshot file in a read-only container, and duplicating contents of the on-line file to the snapshot file, each file initially having an archive bit change number (ABCN) attribute of the same value;modifying the on-line file to reflect changes by a user;asserting the archive bit and incrementing the ABCN of the on-line file in response to the step of modifying;backing up the contents of the snapshot file with the archive bit to a backup file on a secondary storage device;issuing a clear archive bit command upon completion of an incremental backup operation directed to the snapshot file;comparing the ABCN attribute of the on-line file with the ABCN attribute of the backup file;maintaining assertion of the archive bit in the on-line file if the ABCN attributes of an on-line file ID and a snapshot file ID do not match; andclearing the archive bit in the on-line file if the ABCN attributes of the on-line file ID and the snapshot file ID match, thereby enabling an accurate incremental backup operation.