Patent ID: 8473773

Claim:
A computer-implemented method comprising: using one or more processors to perform operations of: establishing a system compliance clock (SCC) for a storage system that provides a compliant storage service, the storage system associated with a plurality of volumes, a current value of the SCC being periodically updated; establishing, for a volume from the plurality of volumes, a volume compliance clock (VCC), the volume compliance clock maintaining a current value of the VCC; storing a SCC reference value on the volume, the SCC reference value reflecting a time stamp of a last update of the current value of the VCC; determining an updated value of the VCC as a sum of the current value of the VCC and an elapsed time value, the elapsed time value is determined by subtracting the SCC reference value from the current value of the SCC; updating the current value of the VCC with the updated value of the VCC; and updating the SCC reference value with the current value of the SCC.