Patent ID: 8612395

Claim:
A server apparatus comprising one or more processors, the server apparatus is a first server apparatus communicatively coupled to a client apparatus, a first storage apparatus that stores a plurality of files, and a second server apparatus that is communicatively coupled to a second storage apparatus, wherein the first server apparatus is configured to: perform writing or reading of data of a file stored in the first storage apparatus, when receiving an access request to the file from the client apparatus; manage a user quota that is information defining a limit of a used amount of storage resources by each user; perform management based on the user quota where the file owned by a user is set as a target of migration to the second storage apparatus, when the used amount of the user exceeds a threshold based on the user quota; exclude the file, out of other of the files specified as targets of migration, used by a plurality of users from a target of the management based on the user quota, and set the file as a target of management based on a file quota that is information defining a limit of capacity for each file, the file quota configured from a plurality of parts of the user quota supplied from each of users who use the file; and stub the file by deleting entity of the file from the first storage apparatus and leaving metadata of the file, when the file has not been accessed by other users for a period of time, if the file is the target of management based on the user quota, collect a respective user quota from each of users who use the file according to access frequency to the file by the user, and set the collected user quota as the file quota when setting the file as a target of the management based on the file quota.