A method and apparatus for maintaining consistency of data stored in the mirror device group

摘要

(57) In the embodiment of the [summary] one, in the data mirroring system, if mirroring communication to the first target storage device is disabled from the first source storage device, the second target storage from the second source storage device I to disable mirroring communication to the device. In another embodiment, the at least one mirror sources plurality of storage devices that the data mirroring system and maintain a data representation consistent subsets on the corresponding at least one target storage devices is preferable that one I want to store information identifying a subset of Tsu. In another embodiment, the first state, second state, and is placed in one of the third state, at least one of the mirror sources plurality of storage devices further. and allow in response to the source storage system receives a write request command chain that is addressed to the mirror source storage device is in a first state and commit the command chain, and written by the command chain will be transferred to the target storage device to the corresponding data was. In response to the source storage system receives a write request command chain that is addressed to the mirror source storage device is in a second state, it is prohibited to commit the command chain. and transferred to the target storage device in response to the source storage system receives a write request command chain that is addressed to the mirror source storage device is in the third state, the corresponding data written by the command chain Allow without, to commit the command chain.