Patent ID: 8554808
Filing Date: 2013-10-08
Classification: G06F

Abstract:
1. A file storage having a first file system, which is coupled to one or more sub-storages, one or more client computers and one or more management computers via a network, comprising: a hierarchical management unit which provides the first file system and a unified file system comprised of one or more second file systems that the one or more sub-storages have, with the one or more client computers; a file service unit which receives an access request from the one or more client computers to the unified file system, converts the access request to an access request to the first file system or the one or more second file systems that compose the unified file system, and accesses any one of the first file system or the one or more second file systems based on the converted access request; an information storage unit which holds client management information for identifying one or more client computers which share each file or each folder for each file or each folder in the unified file system; a migration processing unit which migrates a target file or a target folder which is stored in any of the first file system or the one or more second file systems based on a migration instruction of the target file or the target folder in the unified file system, to the other of the first file system or second file systems; and a migration information notification unit which specifies one or more client computers which share the target file or the target folder by use of the client management information before migration execution of the target file or the target folder and notifies migration information as to migration of the target file or the target folder for each of the specified one or more client computers, wherein: the migration processing unit determines a start time for starting migration of the target file or the target folder, the migration information notification unit notifies each of the specified one or more client computers of the migration information prior to a predetermined time other than the start time, and the migration processing unit waits for the start time, and when receiving a migration suspension request or a migration postponement request from any of the specified one or more client computers while waiting, suspends or postpones migration of the target file or the target folder.