Patent ID: 8935501
Filing Date: 2015-01-13
Classification: G06F

Abstract:
1. A control method comprising: allocating a plurality of virtual disks to a virtual storage allocated to a physical storage; associating data with one of the plurality of virtual disks which has been instructed to store the data and storing the data in the physical storage; calculating an available buffer size of a write buffer; and selecting, by a processor, one of the plurality of virtual disks as a data movement target virtual disk from which data is to be moved in accordance with the calculated buffer size when free space in the virtual storage exceeds a threshold value, wherein, when the calculated buffer size is larger than a certain size, at least one of the plurality of virtual disks whose amount of practical use is smaller than a certain amount and whose increase in data storage capacity is larger than a certain value is selected as the data movement target virtual disk, and wherein, when the calculated buffer size is smaller than the certain size, at least one of the plurality of virtual disks whose amount of practical use is smaller than the certain amount and whose increase in data storage capacity is smaller than the certain value is selected as the data movement target virtual disk.