Patent ID: 8607012

Claim:
A storage system that receives a write command and a write data element, which is one unit of write data, from a computer, the storage system comprising: a physical storage device that constitutes the basis of a journal area and one or more logical volumes comprising a first logical volume; and a controller that receives the write command and the write data element from the computer, and writes the write data element to the first logical volume specified from the write command, wherein the journal area is a storage area in which is stored a journal data element, which is a data element that is stored in any block of a plurality of blocks configuring a logical volume, or a data element that is written to the block, wherein the controller comprises: a size receiver that receives a write unit size, which is the size of the write data element received from the computer; and a size setting unit that sets the received write unit size in the memory for the one or more logical volumes, wherein the size of a journal data element stored in the journal area and based on the set write unit size is the write unit size; and a restore processor that prepares a third logical volume indicating the first logical volume of a restore-targeted generation, wherein the data stored in the third logical volume is backed up in a slot size unit that is larger than the write unit size, wherein the memory comprises a cache memory, and wherein the restore processor reserves, in the cache memory, a slot that is a region of the slot size, stores a plurality of data elements corresponding to the restore-targeted generation in the reserved slot, and backs up the slot size worth of data, which is the data element group stored in the slot.