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AssigneeNetApp, Inc.
InventorsAnshul Pundir, Ashwin Pednekar, Srinath Krishnamachari, Ling Zheng
Estimating the term…
A deferred refcount update technique efficiently frees storage space for metadata (associated with data) to be deleted during a merge operation managed by a volume layer of a node. The metadata is illustratively volume metadata embodied as mappings from logical block addresses (LBAs) of a logical unit (LUN) to extent keys maintained by an extent store layer of the node. One or more requests to delete (or overwrite) an LBA range within a LUN may be captured as page keys associated with metadata pages during the merge operation and the storage space associated with those metadata pages may be freed in an out-of-band fashion. The page keys of the metadata pages may be persistently recorded in a reference count (refcount) log to thereby allow the merge operation to complete without resolving deletion of the keys. A batch of page keys may be organized as one or more delete requests and, once the merge completes, the keys may be inserted into the refcount log. Subsequently, a deferred reference count update process may be spawned (instantiated) to walk through the page keys stored in the refcount log and delete each key, e.g., from the extent store layer, independently and out-of-band from the merge operation.
A method comprising:
A method comprising:
A system comprising:
Dependencies are inferred from the claim text.