Patent ID: 8468517

Claim:
A method for replacing an entirety of an existing storage subsystem with an upgraded storage system, and pursuant to the replacing, at least one upgraded component of a plurality of upgraded components making up the upgrade storage system is connected to at least one existing component of a plurality of existing components making up the existing storage system, the method comprising: creating support for a verify I/O command to be operable on the upgraded storage subsystem; creating a target volume in the upgraded storage subsystem having a same volume identification as a source volume in the existing storage subsystem; configuring a network port to have a same identification as a source port in the existing storage subsystem; and for a command received on the at least one of the plurality of upgraded components, invoking the verify I/O command on at least one of a comparable one of the plurality of existing components to verify the command, wherein if the command is verified, driving the command; wherein pursuant to creating the target volume having the same volume identification as the source volume, the at least one of the plurality of upgraded components disguises at least one of a true volume and port identification of the target volume from the at least one of the plurality of existing components by presenting at least one of a true volume and port identification of the source volume as the at least one of the true volume and port identification of the volume.