Patent ID: 8209292

Claim:
A storage system, comprising: a first storage apparatus coupled to a client computer and including; a first processor, a first memory storing a program executed by the first processor, a first storage area storing a plurality of file data which are access targets of the client computer, and a second storage area storing backup data of the file data by control of the first processor; and a second storage apparatus coupled to the first storage apparatus and including; a second processor, a second memory storing a program executed by the second processor, and a third storage area storing the file data migrated from the first storage area by control of the first and second processors, wherein when backup of the plurality of file data from the first storage area to the second storage area is executed, the first processor creates copy data of the plurality of file data as backup data and stores the backup data in the second storage area, and manages a first time at which the backup data is created, and, when one or more first file data included in the plurality of file data is migrated from the first storage area to the third storage area, the first processor creates a stub indicating a storage location for the first file data in the third storage area, stores the stub in place of the first file data in the first storage area, and sends the first file data to the third storage area, and the second processor stores the first file data, received from the first storage apparatus by control of the first processor, in the third storage area, and manages a second time at which each of the first file data is migrated, and when the plurality of file data of the first storage area is recovered using the backup data in the second storage area, the first processor replaces the plurality of file data in the first storage area with the backup data in the second storage area, and sends the first time to the second storage apparatus, the second processor compares the first time received from the first storage apparatus with the second time for each of the one or more first file data stored in the third storage area, and extracts first file data from the one or more first file data for which the second time is newer than the first time, and the first processor restores a stub indicating a storage location in the third storage area of the extracted first file data, and stores the stub in the first storage area.