Patent ID: 7152146

Claim:
A network-connected storage system comprising a first group of storage devices on which logical storage areas are constructed, a second group of storage devices on which logical storage areas are constructed, and a storage control unit for controlling the first and second groups of storage devices, the storage control unit comprising: a first interface for connecting the first group of storage devices; a second interface for connecting the second group of storage devices; a memory holding a first set of information on the characteristics, including the type of the interface with the storage control unit, of the first and second groups of storage devices and a second set of information on the logical storage areas constructed on the first and second groups of storage devices; a means of referencing the first and second sets of information in the memory in selecting a logical storage area into which the contents of a specified logical storage area constructed on the first or second group of storage devices are to be replicated; a means of checking whether free logical storage areas are available on a group of storage devices having the same interface as the first or second interface, based on the results of referencing the first and second sets of information using the means of referencing; and a means of securing, in the free logical area found to be available using the means of checking such availability, an area for storing a replication of the contents of the specified logical storage area in the first or second group of storage devices.