Patent ID: 7580961
Filing Date: 2009-08-25
Classification: G06F,Y10S

Abstract:
1. A method of processing data in a computer system comprising at least one host and at least one content addressable storage (CAS) system, wherein the at least one host identifies units of data on the at least one CAS system using content addresses each generated based, at least in part, on at least a portion of the content of the corresponding unit of data, the at least one CAS system storing at least one unit of data having a previously-defined retention period, the method comprising acts of: (A) receiving, at the at least one CAS system, a request from the at least one host to reduce a length of the retention period for the at least one unit of data, the retention period specifying a time during which the at least one unit of data cannot be deleted from the at least one CAS system; (B) reducing the length of the retention period for the at least one unit of data in response to the request; (C) maintaining on the at least one CAS system at least one record for the unit of data, the at least one record storing a history of the reduction of the previously defined retention period; (D) receiving at the at least one CAS system, a request from the at least one host to restore the retention period to the length of the previously-defined retention period for the at least one unit of data; and (E) restoring the retention period to the length of the previously-defined retention period in response to the request.