Data replication in a storage system
AssigneeHitachi, Ltd.
InventorsAi SATOYAMA, Noboru MORISHITA, Yasutomo YAMAMOTO
Life of this patent
Estimating the term…
Abstract
For a storage system having plural control units to which plural disk devices are connected, in the method for creating replication in a volume of the disk devices connected to different control units, when receiving update I/O of a replication source during an initial copy for replication, the reflection of update to the replication destination is performed on an extension of the same I/O. When a pair is divided after the completion of copying, the update position is retained on the differential bitmap disposed in the individual control units, and the differential bitmap is merged to one of the control units at a time of resynchronization to perform copy processing.
Claims16
A storage system coupled to a host computer through a network, the storage system comprising:
- a first interface adapter coupled to a host computer through the network;
- a plurality of first disk devices including a first volume;
- a first control unit coupled to the first interface adapter and the first disk devices, the first control unit including a first processor and a first switch;
- a second interface adapter coupled to the host computer through the network;
- a plurality of second disk devices including a second volume;
- a second control unit coupled to the second interface adapter, the second control unit including a second processor and a second switch and a memory storing data sent from the host computer to the second volume temporarily;
- and
- a connection line connected to the first switch of the first control unit and the second switch of the second control unit, wherein the first control unit controls Input/Output (I/O) requests to the first volume, and the second control unit controls I/O requests to the second volume,
- wherein when data stored in the first volume is copied to the second volume,
- wherein the first control unit reads data stored in the first volume, and sends a write request regarding the data stored in the first volume to the second storage system through the first switch, the connection line and the second switch,
- wherein the second control unit secures a region for data of the write request in the memory of the second control unit, and
- wherein the first control unit transfers the data of the write request through the first switch, the connection line and the second switch to the secured region in the memory of the second control unit, and the second control unit writes the data stored in the memory in the second volume.
A storage system coupled to a host computer through a network, the storage system comprising:
- a first interface adapter coupled to a host computer through the network;
- a plurality of first disk devices including a first volume;
- a first control unit coupled to the first interface adapter and the first disk devices, the first control unit including a first processor and a first switch;
- a second interface adapter coupled to the host computer through the network;
- a plurality of second disk devices including a second volume;
- and
- a second control unit coupled to the second interface adapter, the second control unit including a second processor, a second switch and a memory,
- wherein the first control unit controls Input/Output (I/O) requests to the first volume, and the second control unit controls I/O requests to the second volume,
- wherein when a data stored in the first volume is copied to the second volume,
- wherein the first control unit reads data stored in the first volume, and sends a write request regarding the data stored in the first volume to the second storage system through the first interface adapter, the network, and the second interface adapter,
- wherein the second control unit secures a region for data of the write request in the memory of the second control unit,
- wherein the first control unit transfers the data of the write request through the first interface adapter, the network, and the second interface adapter to the secured region in the memory of the second control unit, and
- wherein the second control unit writes the data stored in the memory in the second volume.
Dependencies are inferred from the claim text.