Patent ID: 9110812
Filing Date: 2015-08-18
Classification: G06F

Abstract:
1. A virtual tape comprising: a memory to record logical volume information including an identifier of a logical volume, an identifier of a physical volume storing the logical volume, and information indicating whether the logical volume is cached in a cache unit; a determining unit configured to receive a copy command to copy a plurality of logical volumes stored in one or more first physical volumes to a second physical volume, the copy command including a numerical order for copying the plurality of logical volumes and to determine, based on the logical volume information, whether logical volumes cached in the cache unit are among the plurality of logical volumes in the copy command; and a storage unit configured to store the logical volumes cached in the cache unit to the second physical volume, without reference to the numerical order for copying the plurality of logical volumes included in the copy command, when the cache is full and the determining unit determines the logical volumes cached in the cache unit are among the plurality of logical volumes in the copy command.