Patent attributes
A computer-implemented method for copying data from a source medium to a target medium in a storage system by a computer system, the storage system including a storage device, a first drive configured to access the source medium, and a second drive configured to access the target medium, the method comprising: estimating a waiting time for copy target data to be transferred from the source medium, selecting migration target data of the storage device based on whether migration of data to the target medium is expected to be finished within the waiting time or not, migrating the migration target data from the storage device to the target medium by the second drive while locating and/or reading the copy target data on the source medium by the first drive, and writing the copy target data to the target medium by the second drive.