Snapshot system
AssigneeHitachi, Ltd.
InventorsAi Satoyama, Yoshiaki Eguchi, Takahiro Nakano
Life of this patent
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Abstract
A storage system including a snapshot volume arranged to provide each of a plurality of snapshot generations to the host as a virtual volume and to store data having an identical content in one storage area, and in that a management unit is arranged to: determine, when the host sends a request to create the original volume as a new volume of a designated generation, whether the designated generation is a generation of the copy volume or not; overwrite data in the copy volume for a block address of the designated generation indicating the snapshot volume if the generation of the copy volume is different from the designated generation; and change mapping information of the copy volume to the mapping information of the original volume.
Claims15
A storage system comprising:
- a disk device which comprises:
- an original volume for storing data which is read/written by a host;
- and
- a snapshot volume for storing snapshot data of a plurality of snapshot generations of the original volume;
- and
- a storage control unit which comprises:
- a management unit for managing the storage control unit;
- a channel I/F that is connected to the host;
- and
- a device I/F that is connected to the disk device,
- characterized in that:
- the disk device further comprises a copy volume for storing a copy of the original volume at a predetermined timing,
- the snapshot volume is arranged to provide each of said plurality of snapshot generations to the host as a virtual volume and to store data having an identical content in one storage area, and in that
- the management unit is arranged to:
- determine, when the host sends a request to create the original volume as a new volume of a designated generation, whether the designated generation is a generation of the copy volume or not;
- overwrite data in the copy volume for a block address of the designated generation indicating the snapshot volume if the generation of the copy volume is different from the designated generation;
- and
- change mapping information of the copy volume to the mapping information of the original volume.
A method of managing volumes in a storage system,
- the storage system comprising:
- a disk device which comprises:
- an original volume for storing data which is read/written by a host;
- and a snapshot volume for storing snapshot data which is a snapshot of a plurality of snapshot generations of the original volume;
- and a storage control unit which comprises:
- a management unit for managing the storage control unit;
- a channel I/F that is connected to the host;
- and a device I/F that is connected to the disk device, characterized in that:
- the disk array device further comprises a copy volume for storing a copy of the original volume at a predetermined timing;
- the snapshot volume is arranged to provide each of said plurality of snapshot generations to the host computer as a virtual volume and to store data having an identical content in one storage area, and in that:
- the method, which is performed by the management unit, comprises the steps of:
- determining, when the host sends a request to create the original volume as a new volume of a designated generation, whether the designated generation is a generation of the copy volume or not;
- overwriting data in the copy volume for a block address of the designated generation indicating the snapshot volume if the generation of the copy volume is different from the designated generation;
- and
- changing mapping information of the copy volume to the mapping information of the original volume.
A program for managing volumes, which is used in a storage system comprising:
- a disk device which comprises:
- an original volume for storing data which is read/written by a host;
- and a snapshot volume for storing snapshot data which is a snapshot of a plurality of snapshot generations of the original volume;
- and a storage control unit which comprises:
- a management unit for managing the storage control unit;
- a channel I/F that is connected to the host;
- and a device I/F that is connected to the disk device, characterized in that:
- the disk array device further comprises a copy volume for storing a copy of the original volume at a predetermined timing;
- the snapshot volume is arranged to provide each of said plurality of snapshot generations to the host computer as a virtual volume and to store data having an identical content in one storage area, and in that:
- the program controls the management unit to execute the procedures of:
- determining, when the host sends a request to create the original volume as a new volume of a designated generation, whether the designated generation is a generation of the copy volume or not;
- overwriting data in the copy volume for a block address of the designated generation indicating the snapshot volume if the generation of the copy volume is different from the designated generation;
- and
- changing mapping information of the copy volume to the mapping information of the original volume.
Dependencies are inferred from the claim text.