Patent ID: 9116914
Filing Date: 2015-08-25
Classification: G06F

Abstract:
1. A method for migrating data between tiers of a storage system, the method comprising: subdividing a storage capacity of the storage system into a set of territories; partitioning the set of territories into a plurality of tiers, with each tier having different cost and performance parameters; imposing a hierarchy on the plurality of tiers; overriding a default migration policy by receiving a user-specified policy for data migration for a subset of the plurality of tiers, wherein the subset is less than the plurality of tiers, based at least on an age of data, the user-specified policy comprising respective values for user-specified migration ages and respective user-specified percentages of occupancy for each of the tiers that comprise the subset of tiers; and moving data from a current tier to a destination tier in the hierarchy, wherein at least the current tier belongs to the subset of tiers having a user-defined migration policy, based on the respective value for the user-specified migration age under the condition that an available capacity of the current tier exceeds the respective value for the user-specified percentage of occupancy.