Quantum Corporation
Automated storage tier copy expiration

Abstract:

Example methods and apparatus release storage locations in a tiered storage system by deleting expired tier-copies of a file stored in the tiered storage system. One embodiment includes a policy-class circuit that defines a tier-copy policy associated with a tier, where the tier-copy policy includes an expiration interval (EI) associated with the tier, and a schedule associated with the tier. A copy expiration circuit checks, according to the schedule, for expiration-eligible tier-copies of a file stored in the tiered storage system based, at least in part, on an EI associated with a tier, and on an access time (AT) associated with the file, where the AT denotes the last time the file was accessed. The copy expiration circuit, upon determining that a tier-copy is expiration eligible, declares the tier-copy as expiration eligible. A delete/restore circuit, upon the copy expiration circuit declaring that the tier-copy is expiration eligible, deletes the tier-copy.