A cache device and a method for controlling cached data that enable
efficient use of a storage area and improve the hit ratio are provided.
When cache replacement is carried out in cache devices connected to each
other through networks, data control is carried out so that data blocks
set to a deletion pending status in each cache device, which includes
lists regarding the data blocks set to a deletion pending status, in a
cache group are different from those in other cache devices in the cache
group. In this way, data control using deletion pending lists is carried
out. According to the system of the present invention, a storage area can
be used efficiently as compared with a case where each cache device
independently controls cache replacement, and data blocks stored in a
number of cache devices are collected to be sent to terminals in response
to data acquisition requests from the terminals, thereby facilitating
network traffic and improving the hit rate of the cache devices.