Patent ID: 6968347

Claim:
A method for facilitating the recovery of data that is stored redundantly wherein a first data store acts as a standard physical mirror for storing a primary copy of the date for interaction with a host, said method comprising the steps of: A) defining a second data store operable in a first mode to receive data from the first data store thereby to act as a mirror to the first data store and operable in a second mode wherein the first and second data stores are detached while the host continues to interact with the first data store, B) defining a third data store that receives data from the second data store thereby to synchronize the third data store to the second data store to mirror the second data store in said second mode while the host continues to interact with the first data store, C) issuing a command to establish a third mode for the second data store wherein data in the second data store is replaced with data from the third data store while the second data store is detached from the first data store, D) identifying the data to be transferred in response to the command, and E) copying the identified data from the third data store to the second data store in response to the issuance of the command and identification of data thereby to restore the second data store to a state that existed at the time of a prior transfer of the second data store from the first mode to the second mode.