Restoring data from point-in-time representations of the data
AssigneeHewlett-Packard Development Company, L.P.
InventorsChoon-Seng Tan, Greg J. Pellegrino, Balaji Natrajan
Life of this patent
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Abstract
A system includes a controller to store point-in-time representations (or snapshots) of data taken at different time points from storage unit of a storage subsystem. Data can be restored from one of the point-in-time representations, with point-in-time representations taken later than the one point-in-time representation maintained enabled to allow a subsequent restoring of data from the later point-in-time representations.
Claims25
A method for use in a system, comprising:
- storing plural point-in-time representations of data taken at plural respective time points from a storage unit;
- receiving a first request to restore data from a first one of the point-in-time representations;
- and
- in response to the first request to restore but prior to performing the restore, storing data in the storage unit in another point-in-time representation.
An article comprising at least one storage medium containing instructions that when executed cause a system to:
- store plural point-in-time representations of data taken at respective time points from a storage unit;
- perform a restore from a first one of the point-in-time representations;
- and
- maintain other point-in-time representations enabled to allow a subsequent restore of data from a second one of the point-in-time representations taken subsequently to the first one of the point-in-time representations.
A system comprising:
- a storage containing a storage unit, plural point-in-time representations of the storage unit, and an indicator;
- and
- a controller adapted to perform one of a single-direction restore and a dual-direction restore from the point-in-time representations based on a state of the indicator.
A controller for controlling a storage subsystem, comprising:
- a data access module to store data in a logical storage unit of the storage subsystem;
- and
- a snapshot module to:
- store plural snapshots of data taken at plural corresponding time points;
- receive a first request to restore data from one of the snapshots;
- and
- in response to the first request but prior to performing the restore, copy data in the logical storage unit to another snapshot.
A system comprising:
- means for storing plural snapshots of data taken at respective plural time points;
- means for restoring a first one of the snapshots;
- and
- means for maintaining other snapshots enabled to allow a subsequent restore of data from a second one of the snapshots taken subsequently to the first one of the snapshots.
Dependencies are inferred from the claim text.