A method and apparatus for data recovery in a system involving a first data store
acting as a standard volume and a physical moving mirror data store that operates
in a first mode to be synchronized and in a second, isolated mode. A third physical
mirror data store synchronizes with the second data store in its second operating
mode. In response to a command to establish a third or reverse split operating
mode, the data to be transferred in response to that command is identified. Copying
of the identified data then commences from the third data store to the second data
store to recover any data that may have been corrupted in the second data store.