Method and apparatus for de-duplication after mirror operation
AssigneeHitachi, Ltd.
InventorYoshiki Kano
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Abstract
During mirroring operations, de-duplication operations are applied to the mirror volumes. Data stored to a first volume is mirrored to a second volume. The second volume is a virtual volume having a plurality of logical addresses, such that segments of physical storage capacity are allocated for a specified logical address as needed when data is stored to the specified logical address. A de-duplication operation is carried out on the second volume following a split from the first volume. A particular segment of the second volume is identified as having data that is the same as another segment in the second volume or in the same consistency group. A link is created from the particular segment to the other segment and the particular segment is released from the second volume.
Claims7
A storage system comprising:
- a first controller including a central processing unit (CPU) and a memory;
- and
- a plurality of storage devices provided as a plurality of storage volumes to a host by said first controller,
- wherein said first controller stores write data received from said host to a first storage volume of said plurality of storage volumes and mirror the write data to a second storage volume of said plurality of storage volumes in sync operation,
- wherein a de-duplication operation is performed against the second storage volume, wherein before the de-duplication operation the first controller suspends the sync operation, and
- wherein in restore operation the first controller reverse resynchronizes data against the first storage volume, and during said restore operation the storage system is capable of receiving write operations from the host.
Dependencies are inferred from the claim text.