Patent ID: 7287136

Claim:
A first cache device for storing data received through a network as cached data and for retrieving the cached data in response to a data request from a terminal to send the cached data to the terminal, the first cache device comprising: a first data area for storing data; a second data area for storing a cache group table including group configuration information regarding a cache group including first data associated with the first cache device, second data associated with one or more additional cache devices, wherein the additional cache devices are connected to the same network as the first cache device and the additional cache devices are members of the cache group, and including identifying data associated with content data being controlled by the cache group; a controller for determining which data blocks are in a deletion pending status, the data blocks being data stored in the first cache device, the data blocks being associated with the content data being controlled by the cache group, and for controlling a status of the data blocks in the deletion pending status according to a deletion pending list including entries having information corresponding to the data blocks in the deletion pending status.