Patent ID: 8370592

Claim:
A method of migrating data from storage devices of a set of source arrays to storage devices of a set of target arrays, each storage device being capable of operating in (i) an active mode in which that storage device is permitted to perform host read and write operations and (ii) a passive mode in which that storage device is not permitted to perform host read and write operations, the method comprising: while a host initially accesses host data from the set of source arrays using multipath I/O software, providing active-to-passive instructions to the set of source arrays, the active-to-passive instructions identifying the storage devices of the set of source arrays to be transitioned from the active mode to the passive mode; during a predefined time period, monitoring whether the storage devices of the set of source arrays have transitioned from the active mode to the passive mode in response to the active-to-passive instructions; after the predefined time period, (i) if all of the storage devices of the set of source arrays have transitioned from the active mode to the passive mode, operating the storage devices of the set of target arrays in the active mode and beginning a data transfer operation which transfers data from the storage devices of the set of source arrays to the storage devices of the set of target arrays to enable the host to access the host data from the set of target arrays using the multipath I/O software, and (ii) if at least one storage device of the set of storage devices of the set of source arrays has not transitioned from the active mode to the passive mode, providing passive-to-active instructions to the set of source arrays, the passive-to-active instructions identifying the storage devices of the set of source arrays to be transitioned from the passive mode back to the active mode to enable the host to access the host data from the set of source arrays using the multipath I/O software.