Storage apparatus, and storage control method using the same
AssigneeHitachi, Ltd.
InventorsKoji Nagata, Masaaki Kobayashi
Life of this patent
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Abstract
The present invention aims at providing a storage apparatus that does not increase the I/O load on a primary volume, even if there are several secondary volumes for which data consistency with the primary volume should be guaranteed. A storage apparatus writes write data for write access directed to a primary volume P to a secondary volume S1. A controller in the storage apparatus copies that write data from the secondary volume S1 to secondary volumes. S2 and S3 in background processing. The storage apparatus uses bitmaps to manage data in the secondary volume S1 shared by each of the secondary volumes S2 and S3.
Claims18
A storage apparatus comprising:
- a storage unit;
- a controller for providing a host computer with a storage area in the storage unit as a plurality of volumes, and controlling access from the host computer to the volumes;
- and
- memory in which management information for managing the volumes is set,
- the controller being configured to control, in accordance with the management information, writing write data sent from the host computer to the volumes,
- wherein the plurality of volumes includes a primary volume that the host computer write-accesses and a plurality of secondary volumes that functions as a replicated volume for the primary volume, and the plurality of secondary volumes comprises a main-volume to which write data for write access from the host computer directed to the primary volume is written and a sub-volume that is subordinate to the main-volume, and
- wherein the controller is configured to write, upon receipt of the write access from the host computer, the write data to the primary volume and the main-volume, and also write the write data that has been written to the main-volume to the sub-volume.
A storage control method using a storage apparatus that provides a host computer with storage volumes and controls write access from the host computer to the storage volumes, the method comprising:
- under control of the storage apparatus,
- generating, as the storage volumes, a primary volume that the host computer accesses and a plurality of secondary volumes that functions as a replicated volume for the primary volume;
- defining the plurality of secondary volumes as comprising a main-volume to which write data for write access from the host computer directed to the primary volume is written and a sub-volume that is subordinate to the main-volume;
- and
- upon receipt of the write access from the host computer, writing the write data to the primary volume and the main-volume, and also writing the write data that has been written to the main-volume to the sub-volume.
Dependencies are inferred from the claim text.