Patent ID: 8713307

Claim:
A computer system comprising: a memory resource to be accessed by a host computer; a storage system for providing a volume, whereby a logical memory resource is created, to the host computer, the storage system including: a first storage system that has a first parity group and sets a first volume to the first parity group; and a second storage system that has a second parity group and sets a second volume to the second parity group; and a management device for managing migration of the volume; wherein the second volume is the migration destination object; wherein the management device controls the first storage system and the second storage system in order to execute the volume migration processing between the first and the second volume; wherein, when detecting a task of migration of the volume based on a request from a first administrator, the management device compares an encryption function setting status of the volume with the encryption function setting status of a migration destination object of the volume; and sends notice of this comparison result to a second administrator, who is different from the first administrator, for security management of the storage system; wherein, if the management device compares an encryption level of the second volume with the encryption level of the first volume and determines that the former encryption level is lower than the latter encryption level, the management device sends notice of this result as a first judgment result to the second administrator; wherein, if the management device compares an encryption key backup type of the second volume with the encryption key backup type of the first volume and determines that the former encryption key backup type is inferior to the latter encryption key backup type, the management device sends notice of this result as a second judgment result to the second administrator; and determines whether or not it is necessary to continue the volume migration request from the first administrator, based on a request from the second administrator who has received the notice; wherein, if it is determined that the first volume is encrypted and the second volume is not encrypted, the management device notifies the second administrator of the first judgment result; and wherein, if both the first volume and the second volume are encrypted and the encryption key backup type of the first volume is the same as the encryption key backup type of the second volume, the management device has the first storage system and the second storage system execute processing for migrating the volume from the first volume as a migration source to the second volume as a migration destination without requiring the second judgment result; and if the encryption key backup type of the first volume is different from the encryption key backup type of the second volume, the management device notifies the second administrator of the second judgment result.