Hewlett Packard Enterprise Development LP

Richard Phillip Mayo

David Malcolm Falkinder

Peter Thomas Camble

Callum Murray

Aman Sahil

Andrew Todd

Alastair Michael Slater

Russell Ian Monk

Treeve White

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; generating a manifest to record a received order of the data units; indexing the data units in container indexes, where each container index records fingerprints and immutable storage locations of one or more data units; in response to a determination that the manifest has reached a threshold size, determining immutable storage locations that are recorded in the container indexes; and updating the manifest to record the determined immutable storage locations.

Storage location metadata for a deduplication storage system

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 receiving data units of a backup stream to be stored in a deduplication storage system; performing a first matching operation to match the data units against a first container index of a plurality of container indexes, where the plurality of container indexes comprise metadata indicating storage locations of data units previously stored in the persistent storage; calculating a first ratio indicating the amount of deduplication that occurred during the first matching operation against the first container index; and in response to a determination that the first ratio violates a condition with respect to local ratio history data of the first container index, identifying at least one portion of the backup stream as being potentially affected by a ransomware attack.

Ransomware detection in 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 journals for metadata changes. An example includes detecting, by a storage controller of a deduplication storage system, a cloning operation of a manifest range; loading a journal from persistent storage into memory in response to the detected cloning operation, wherein the journal is to store changes to a container index associated with the manifest range, and wherein the container index is not loaded into the memory in response to the detected cloning operation; and updating the journal in the memory to include an indication of changes to metadata of the container index that is not loaded into the memory, wherein the changes to the metadata are associated with the detected cloning operation.

Journals for data cloning operations

Example implementations relate to metadata operations in a storage system. An example includes a machine-readable medium storing instructions that upon execution cause a processor to: receive a data stream to be stored in persistent storage of a deduplication storage system; store data units of the data stream in a container entity group object according to arrival time, where the data units of the container entity group object are referenced by a plurality of container indexes; generate a data index to list each container index that references at least one data unit included in the container entity group object; and in response to a determination that the total size of the container entity group object exceeds the threshold size, transfer the container entity group object from memory to the persistent storage.

Data index for deduplication storage system

Example implementations relate to metadata operations in a storage system. An example includes generating, by a storage controller of a deduplication storage system, a candidate list of container indexes for matching operations of a received data segment, each container index in the candidate list having an associated match cost; identifying, by the storage controller, a journal group associated with a first container index listed in the candidate list; reducing, by the storage controller, a match cost associated with the first container index in response to a determination that the identified journal group is in a modified state; and performing, by the storage controller, the matching operations of the received data segment based at least on the reduced match cost of the first container index.

Matching operation for a deduplication storage system

Example implementations relate to deduplication operations in a storage system. An example includes, in response to initiation of a new backup process to store a first stream of data, initializing a temporary sparse index to be stored in a memory of a deduplication storage system; identifying a cloned portion of the first data stream; identifying at least one container index associated with the cloned portion of the first data stream; identifying a set of hook points included in the at least one container index; and populating the temporary sparse index with a set of entries, the set of entries mapping the identified set of hook points to the at least one container index.

Temporary sparse index 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.

Migration of journal groups in a storage system

Example implementations relate to metadata operations in a storage system. An example storage system includes a machine-readable storage storing instructions executable by a processor to determine to generate a synthetic full backup based on data stream representations of a plurality of data streams. The instructions are also executable to, in response to a determination to generate the synthetic full backup, create a logical group including the data stream representations. The instructions are also executable to specify a cache resource allocation for the logical group, and generate the synthetic full backup from data stream representations using an amount of a cache resource limited by the cache resource allocation for the logical group.

Resource allocation for synthetic backups

Examples implementations relate to journals for metadata changes. An example includes detecting, by a storage controller, metadata changes associated with a container index of a deduplication storage system; recording, by the storage controller, the detected metadata changes in a journal associated with the container index, where the journal is included in a journal group comprising a plurality of journals; determining, by the storage controller, whether a filled amount of the journal exceeds a fill threshold; and, in response to a determination that the filled amount of the journal does not exceed the fill threshold, writing the journal group from memory to persistent storage.

Journals to record metadata changes in a storage system

Example implementations relate to storing manifest portions in a metadata cache. An example includes receiving, by a storage controller, a read request associated with a first data unit. In response to receiving the read request, the storage controller stores a manifest portion in a metadata cache, the stored manifest portion comprising a plurality of records, the plurality of records including a first record associated with the first data unit. The storage controller determines storage information of the first data unit using pointer information included in the first record of the stored manifest portion, and replaces the pointer information in the first record with the determined storage information of the first data unit.

Metadata cache for storing manifest portion

Examples may include storage of a small object representation in a deduplication system. Examples may store the small object representation of an object in the deduplication system based on a determination that the object is smaller than a threshold size. In examples, the small object representation may include a direct reference from a top-level data structure to small object metadata in a bottom-level data structure of the small object representation.

Storage of a small object representation in a deduplication system

Example implementations relate to metadata operations in a storage system. An example method includes receiving, from a first stream process, a first write request for a first container index in memory. The method further includes, in response to a receipt of the first write request, sending a first token to the first stream process without writing the first container index to a persistent storage. The method further includes receiving, from a second stream process, a first completion request for the first container index. The method further includes, in response to a receipt of the first completion request, writing the first container index from the memory to the persistent storage.

Growing community of inventors

Bristol, United Kingdom

Richard Phillip Mayo