Patent ID: 8078819

Claim:
A computer system including a file server and a storage system having a plurality of storage mediums including at least one first type storage medium and at least one second type storage medium of which access speed performance is lower than access speed performance of the at least one first type storage medium, the file server comprising: a network interface for communicating with a client computer; and a processor for managing files stored in a plurality of logical units corresponding to a plurality of file systems, respectively, in the storage system, wherein the processor configures at least one file system of the plurality of file systems, in an integrated logical unit including both the at least one file type storage medium and the at least one second type storage medium, wherein when the network interface receives a first write request of a first file of the file system related to the integrated logical unit from the client computer, the first file including first data and first metadata, the processor registers the first metadata of the first file to the at least one first type storage medium and writes the first data of the first file to the at least one first type storage medium based on file value information, wherein when the network interface receives a second write request of a second file of the file system from the client computer, the second file including second data and second metadata, the processor registers the second metadata of the second file to the at least one first type storage medium and writes the second data of the second file to the at least one second type storage medium based on the file value information, wherein the storage system stores information of address ranges of the integrated logical unit, in which each address range corresponds to at least one first type storage medium and the at least one second type storage medium included in the integrated logical unit, wherein when the first data of the first file is migrated from the at least one first type storage medium to the at least one second type storage medium within the integrated logical unit based on the file value information, the processor modifies the first metadata stored in the at least one first type storage medium, so as to point to a location of the actual data in the at least one second type storage medium.