Patent ID: 7584337
Filing Date: 2009-09-01
Classification: G06F

Abstract:
1. A method of providing historical data for a plurality of units of storage, the method comprising: backing up old data to be overwritten by write command with new data in the plurality of units of storage using a current store and a time store, the current store representing a current state of the plurality of units of storage, the time store storing old data copied from the current store and associated timestamps, the old data copied from the current store representing old data to be overwritten by write command in the plurality of units of storage, wherein old data to be overwritten by write command in the plurality of units of storage is continuously indexed by timestamp in the time store prior to execution of each write command, the current store and the time store being separate from the plurality of units of storage and from each other, wherein the at least one time store does not store the new data; receiving a request for data stored in at least one of the plurality of units of storage at a specified time; and identifying the requested data based at least in part on a timestamp in the time store, without the use of a snapshot that includes the requested data at the specified time.