Patent ID: 7640406

Claim:
In a distributed computing system having a primary storage device, a secondary storage device and a policy engine server, the policy engine server being configured to manage migration of files between the primary and secondary storage devices by migrating data files on the primary storage device to the secondary storage device and replacing the data files on the primary storage device with placeholder files, a method for locating orphan files within the secondary storage device that are not properly referenced by placeholder files on the primary storage device, the method comprising: identifying a secondary file on a secondary storage device, wherein the secondary file corresponds to a data file on a primary storage device that has been replaced with a placeholder file, the secondary file being associated with file identification data, wherein the file identification data includes a content address that references the placeholder file on the primary storage device; identifying the placeholder file on the primary storage device, the placeholder file including an offline reference that identifies a particular secondary file on the secondary storage device; and determining if the offline reference of the placeholder file validly references the content address of the secondary file, wherein the secondary file is identified as an orphan file on the secondary storage device if the secondary file is different from the particular secondary file identified by the offline reference of the placeholder file.