Patent ID: 8275980

Claim:
A server computer, comprising: a virtual computer execution unit that executes a virtual server volume image, the virtual server volume image including a plurality of files relating to an operating system or application programs; a trace data output unit that outputs trace data relating to accesses to the files during execution of the virtual server volume image, the trace data including an access type, an access address, and an access frequency for each of the files of the plurality of files; a judgment unit which judges, for each of the files based on the trace data for the file, whether the file conforms to a first type of file, and, upon judging that the file conforms to the first type of file, judges whether the file conforms to a second type of file, the first type of file having a write access and the second type of file having an area where localized write accesses occur; and a splitting unit that splits each of the files conforming to the second type of file into the area where the localized write accesses occur as a first file categorized as an entity and a remaining area of the file as a second file categorized as a reference.