Hewlett Packard Enterprise Development LP

Callum Murray

Richard Phillip Mayo

Aman Sahil

David Malcolm Falkinder

Example implementations relate to deduplication operations in a storage system. An example includes receiving a stream of data units to be stored in a persistent storage of a deduplication storage system; loading a first container index into the memory to index one or more data units included in the stream; updating the first container index to indicate a storage location of a first data unit included in the stream; reading a manifest list in the first container index to identify a first manifest indexed by the first container index; and, while the first container index remains loaded in the memory to index the one or more data units, in response to a determination that the identified first manifest is included in the first backup item that has been marked for deletion, decrementing a reference count of a second data unit.

Inline housekeeping for a deduplication storage system

Example implementations relate to deduplication operations in a storage system. An example includes generating a housekeeping work map to delete a backup item stored in a deduplication storage system; selecting a first work entry of the housekeeping work map, where the first work entry identifies a first container index and a first manifest; in response to a selection of the first work entry, loading the first container index into the memory, the first container index comprising a back-reference data structure; identifying, in the back-reference data structure, a back-reference entry indexed to the first manifest; determining, using the back-reference entry indexed to the first manifest, a first set of data units included in the first manifest and that are indexed in the first container index; and decrementing, in the first container index, a set of reference counts for the determined first set of data units.

Back-reference data structure for a deduplication storage system

Example implementations relate to metadata operations in a storage system. An example includes detecting, by a storage controller of a deduplication storage system, a housekeeping operation to perform updates to data of a set of container indexes of stored deduplicated data; in response to a detection of the housekeeping operation, the storage controller identifying, among the set of container indexes, a plurality of container indexes associated with a particular journal group, the particular journal group comprising a plurality of journals to store updates to data of the plurality of container indexes, respectively; and maintaining, by the storage controller, the particular journal group loaded in memory until all of the updates of the housekeeping operation to the plurality of container indexes have been stored in the respective journals of the particular journal group.

Journal groups for metadata housekeeping operation

Example implementations relate to metadata operations in a storage system. An example includes receiving, by a storage controller of a deduplication storage system, a plurality of data streams to be stored in persistent storage of the deduplication storage system; identifying, by the storage controller, a set of journals in a first journal group that are modified during a first backup process; determining, by the storage controller, a count of the set of journals that are modified during the first backup process; comparing, by the storage controller, the determined count to a migration threshold; and migrating, by the storage controller, at least one journal of the set of journals to a second journal group based at least on a comparison of the determined count to the migration threshold.

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Bristol, United Kingdom

Callum Murray