CACHING SCHEME SYNERGY FOR EXTENT MIGRATION BETWEEN TIERS OF A STORAGE SYSTEM

摘要

A method according to one embodiment includes determining to move an extent from a source-tier in a storage system to a destination-tier in the storage system; determining whether any track from the set of tracks is presently being written to; designating to a write-stack associated with the source-tier each track that is presently being written to and designating to a read-stack associated with the source-tier remaining tracks from the set of tracks; removing oldest tracks from the read-stack and the write-stack until the read-stack and the write-stack have been depleted of tracks; when a parameter of the extent exceeds a migration threshold: populating a destination-tier cache with the tracks as they are removed from the read-stack and the write-stack using a predetermined read-to-write ratio and removing tracks from a source-tier cache that were removed from the read-stack and the write-stack; and migrating the extent from the source-tier to the destination-tier.