Patent ID: 7133982

Claim:
A method for copying source logical volumes to target logical volumes in a storage control unit that is coupled to a host, the method comprising: performing copy operations on the source logical volumes to copy to the target logical volumes, wherein the copy operations create a consistent copy of the source logical volumes in the target logical volumes; and while performing a copy operation to copy from one source logical volume to one target logical volume, restricting a write operation from being performed on the one source logical volume, until the copy operations have been performed on the source logical volumes, wherein a first write operation received for a first source logical volume is queued in response to determining that the first source logical volume is in a busy state in which write operations are restricted, wherein the first write operation is performed in response to determining that the first source logical volume is in a state in which write operations are not restricted, wherein the copy operations are performed in response to an application in the host generating: (i) an establish copy command that indicates a source volume parameter, a target volume parameter, and a freeze parameter, wherein the establish copy command copies a first logical volume indicated in the source volume parameter to a second logical volume indicated in the target volume parameter, wherein the freeze parameter indicates whether write operations are to be restricted on the first logical volume; and (ii) a copy consistency group command, wherein the copy consistency group command indicates a group of logical volumes on which write operations may resume.