Patent ID: 9600493
Date: 2017-03-21
CPC Classifications: G06F,H04L

Claim:
1. 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, by the computer system, a waiting time for copy target data to be transferred from the source medium; selecting, by the computer system, 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, by the computer system, 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, by the computer system, the copy target data to the target medium by the second drive, wherein the copy target data is a target of an inter-generation copy, wherein the waiting time includes a time required for accumulating predetermined amount of read data into a cache or buffer by the first drive, wherein the time required for accumulating is calculated based on a physical position of the copy target data on the source medium, the physical position of the copy target data including a longitudinal position and a wrap position of start and end positions of the copy target data.