Removing stale hints from a deduplication data store of a storage system
AssigneeHewlett Packard Enterprise Development LP
InventorsNarayanan Balakrishnan, Adil Babu Mohammed
Life of this patent
Estimating the term…
Abstract
Examples include removing stale hints from a data deduplication store (DDS) in a storage system. Some examples incorporate an epoch value in a hint, that is written in the DDS, for data that is present in a snapshot of one of a plurality of virtual volumes in a storage system and use the epoch value to identify a stale hint and remove the stale hint from the DDS.
Claims18
A method for maintaining deduplication in a storage system, comprising:
- receiving, by a storage controller, data to be written to one of a plurality of virtual volumes of a storage system, the storage system including a deduplication data store (DDS) that is shared among the virtual volumes;
- determining, by the storage controller, whether an entry in the DDS, corresponding to the received data, is a hint pointing to a storage location in a snapshot of the virtual volume, wherein the hint comprises an epoch value associated with the snapshot at a first timestamp when the hint was written;
- in response to determining that the entry in the DDS is the hint pointing to the storage location in the snapshot, identifying, by the storage controller, whether the hint is a stale hint based on the epoch value;
- and
- in response to identifying that the hint is the stale hint, removing, by the storage controller, the hint from the DDS.
An article comprising at least one non-transitory machine-readable storage medium storing instructions executable by at least one processor of a storage system to:
- receive data to be written to one of a plurality of virtual volumes of a storage system, the storage system including a deduplication data store (DDS) that is shared among the virtual volumes;
- determine whether an entry in the DDS, corresponding to the received data, is a hint pointing to a storage location in a snapshot of the virtual volume, wherein the hint comprises an epoch value associated with the snapshot at a first timestamp when the hint was written;
- in response to determining that the entry in the DDS is the hint pointing to the storage location in the snapshot, identify whether the hint is a stale hint based on the epoch value;
- and
- in response to identifying that the hint is the stale hint, remove the hint from the DDS.
A storage system comprising:
- at least one processor;
- at least one non-transitory machine-readable storage medium comprising instructions executable by the at least one processor to:
- receive data to be written to one of a plurality of virtual volumes of a storage system, the storage system including a deduplication data store (DDS) that is shared among the virtual volumes;
- determine whether an entry in the DDS, corresponding to the received data, is a hint pointing to a storage location in a snapshot of the virtual volume, wherein the hint comprises an epoch value associated with the snapshot at a first timestamp when the hint was written;
- in response to determining that the entry in the DDS is the hint pointing to the storage location in the snapshot, identify whether the hint is a stale hint based on the epoch value;
- and
- in response to identifying that the hint is the stale hint, remove the hint from the DDS.
Dependencies are inferred from the claim text.