Abstract: 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.

Abstract: 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.

Abstract: Example implementations relate to provisioning a deduplication data store. An example includes receiving inputs indicating an expected data amount and at least one retention period for the deduplication data store; performing a comparison of the at least one retention period to a stored data structure; determining at least one storage multiplier based on the comparison of the at least one retention period to the stored data structure; and determining an amount of storage to provision for the deduplication data store based on the expected data amount and the at least one storage multiplier.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In some examples, in response to an event at the deduplication system, a system accesses item metadata of a backup item that is backed up to a remote object storage system, the item metadata of the backup item including range information indicating a range of identifier values for portion objects of the backup item stored in the remote object storage system. The system issues, based on the range information, requests to obtain respective attribute information of the portion objects of the backup item stored in the remote object storage system. The system determines, based on the attribute information, a name of a given portion object of the backup item already used.

Abstract: Example implementations relate to backups to a secondary storage system of a file system instance that hierarchically relates data objects by content-based signatures to a root object and includes subtrees that correspond to respective inodes. In an example, a list of the content-based signatures is sent to the secondary storage system. Metadata and data of a subtree is stored into an item in the secondary storage system designated for the subtree.

Abstract: Example embodiments relates to method and systems to restore content of a volume at a given point in time.

Abstract: In some examples, a non-transitory machine readable storage medium has machine readable instructions to cause a computer processor to segment a datastream into a plurality of equal length blocks each of which has a fixed length, separately encrypt each equal length block using a first encryption key, swap a subset of bits of a first encrypted equal length block with a subset of bits of a second encrypted equal length block such that both of the blocks each have a length equal to the fixed length, and separately encrypt each block using a second encryption key.

Abstract: Utilizing error correction (ECC) for secure secret sharing includes computing an encrypted key using a key and a number of random values, computing, based on a first ECC scheme, a key ECC for the encrypted key and the random values, and storing a number of key fragments on a number of storage servers, the number of key fragments includes the encrypted key, the random values, and the key ECC.

Abstract: Examples are disclosed including generation of a first erasure coded data portion based on a first data portion of the data object, generation of a second erasure coded data portion based on a second data portion of the data object, formation of a first combined block by combining a first part of the first erasure coded data portion and a first part of the second erasure coded data portion, formation of a second combined block by combining a second part of the first erasure coded data portion and a second part of the second erasure coded data portion, storage of the first combined block in a first storage location, and storage of the second combined block in a second storage location.

Abstract: Examples are disclosed including generation of a first erasure coded data portion based on a first data portion of the data object, generation of a second erasure coded data portion based on a second data portion of the data object, formation of a first combined block by combining a first part of the first erasure coded data portion and a first part of the second erasure coded data portion, formation of a second combined block by combining a second part of the first erasure coded data portion and a second part of the second erasure coded data portion, storage of the first combined block in a first storage location, and storage of the second combined block in a second storage location.

Abstract: A technique includes communicating a plurality of hashes associated with chunks of an object to at least some stores of a plurality of stores on which the object is distributed; and in response to the communication, receiving responses indicating a distribution of the associated chunks. The technique includes selecting one of the stores based at least in part on the responses and communicating deduplicated data associated with the object to the selected store.

Abstract: A technique includes communicating signatures of samples of first data associated with an object to at least some stores of a plurality of stores on which the object is distributed, and in response to the communication, receiving responses indicating numbers of the samples stored on the respective at least some of the plurality of stores and regulating on which store of the plurality of stores deduplicated data associated with the first data is stored based at least in part on the numbers and a pattern of data storage on the stores.