Abstract: A file server holding tag information representative of file contents and an access frequency of each file calculates a tag rating from the access frequency of each file and calculates a file rating from the tag rating affixed to the file. It controls to place a file having a high calculated file rating on a higher transfer performance layer, and place a file having a low calculated file rating on a lower transfer performance layer. Rapid accesses can be handled quickly by placing in advance a file whose access is anticipated to be increased after interest is increased although an access frequency is still low, on a layer having a short response time and high throughput, and by maintaining a file whose access is anticipated to be increased because of increased interest although an access frequency is lowered, on a layer having a short response time and high throughput.

Abstract: MAID (Massive Array of Idle Disks) technology can not stop an array group in a time zone in which if any access is made to the array group desired to be stopped. For realization of power saving, the power may be stopped in a time zone when there is no access, but frequent power-on or power-off has a possibility of shortening the life of a physical disk. In addition, if plural physical disks are collectively activated in a particular period, the power consumption of a storage system as a whole in that period is increased sharply, so that there is a possibility that the stable operation of the storage system is adversely affected. For realizing power saving, plural tasks using the storage system is by scheduled and the task execution and the power-on and power-off of a power controlled unit is controlled based on the schedule selected by a user.

Abstract: A file server holding tag information representative of file contents and an access frequency of each file calculates a tag rating from the access frequency of each file and calculates a file rating from the tag rating affixed to the file. It controls to place a file having a high calculated file rating on a higher transfer performance layer, and place a file having a low calculated file rating on a lower transfer performance layer. Rapid accesses can be handled quickly by placing in advance a file whose access is anticipated to be increased after interest is increased although an access frequency is still low, on a layer having a short response time and high throughput, and by maintaining a file whose access is anticipated to be increased because of increased interest although an access frequency is lowered, on a layer having a short response time and high throughput.

Abstract: MAID (Massive Array of Idle Disks) technology can not stop an array group in a time zone in which if any access is made to the array group desired to be stopped. For realization of power saving, the power may be stopped in a time zone when there is no access, but frequent power-on or power-off has a possibility of shortening the life of a physical disk. In addition, if plural physical disks are collectively activated in a particular period, the power consumption of a storage system as a whole in that period is increased sharply, so that there is a possibility that the stable operation of the storage system is adversely affected. For realizing power saving, plural tasks using the storage system is by scheduled and the task execution and the power-on and power-off of a power controlled unit is controlled based on the schedule selected by a user.

Abstract: The data migration method of this invention is for a computer system. The data migration method is characterized in that the storage system measures, for each logical volume, a used I/O amount and a storage capacity of the logical volume, the management computer manages the logical volumes in groups by storing the association relation between the logical volumes and the groups, the management computer obtains, from the storage system, the used I/O amount of the logical volume and storage capacity, which are measured by the storage system, the management computer identifies a logical volume to which data is to be moved based on the ratio of the obtained I/O amount of the logical volume to the obtained storage capacity of the logical volume, and the management computer instructs the storage system to move data from the data's original logical volume to the logical volume designated as the migration destination.

Abstract: The data migration method of this invention is for a computer system. The data migration method is characterized in that the storage system measures, for each logical volume, a used I/O amount and a storage capacity of the logical volume, the management computer manages the logical volumes in groups by storing the association relation between the logical volumes and the groups, the management computer obtains, from the storage system, the used I/O amount of the logical volume and storage capacity, which are measured by the storage system, the management computer identifies a logical volume to which data is to be moved based on the ratio of the obtained I/O amount of the logical volume to the obtained storage capacity of the logical volume, and the management computer instructs the storage system to move data from the data's original logical volume to the logical volume designated as the migration destination.