Patent ID: 7974953

Claim:
A method comprising: creating a metadata file in a writeable persistent point-in-time image (PPI) at a time of creation of the writeable PPI, the metadata file including a time and date of creation of the writeable PPI independent from a time and date of creation of an underlying PPI on which the writeable PPI is based, the writeable PPI including at least one logical unit at the time of creation; and in response to a deletion of a file system using the writeable PPI, inspecting the writeable PPI to determine whether the writeable PPI has reached an end of a life cycle, including testing the writeable PPI to determine: whether a logical unit included in the writeable PPI has a creation time later than the time of creation of the metadata file, the presence of a creation time of a logical unit after the creation time of the metadata file indicating that an additional logical unit has been created after the creation of the writeable PPI; whether a client is presently mapped to a logical unit within the writeable PPI; whether a client or other entity is the creator of the writeable PPI; wherein an identifier of the creator of the writeable PPI is retrieved from the metadata file and compared with an identifier of a client or other entity attempting to delete the writeable PPI; and whether an additional writeable PPI was created from the writeable PPI.