Patent ID: 7159085
Filing Date: 2007-01-02
Classification: G06F,Y10S

Abstract:
1. A method of allowing point-in-time view of data on a disk, comprising: initiating from a first host, a first session of writing data to a disk which affects a portion of the disk; creating and storing the entry indicative of which portion of the disk for said first session was affected by a write operation, and where data corresponding to said first session writing operation is stored on the disk; initiating and controlling from the first host at least one second session of writing data to a disk at a time different from initiation of the first session, with said at least one second session of writing data affecting a portion of the disk; copying data in any portion of the disk corresponding to said first session which is to be affected by a write operation by said at least one second session; creating and storing entries indicative of where the data for said first session to be affected by the write operation is located, and creating and storing entries indicative of which portion of the disk for said at least one second session was affected by the write operation, and where data corresponding to said at least one second session writing operation is stored on the disk; and conducting point-in-time viewing of the disk from a second host wherein only the second host can access the entries indicative of data corresponding to each session, to view prior session data.