Patent ID: 7941630

Claim:
A storage system coupled to a host computer and a management apparatus, comprising: a plurality of storage devices accessed by the host computer; and a control unit that controls the plurality of storage devices, wherein the control unit: sets a first-type virtual device corresponding to the plurality of storage devices, the first-type virtual device including a plurality of first-type logical devices, wherein the plurality of first-type logical devices includes at least one first first-type logical device and at least one second first-type logical device, the at least one first first-type logical device being allocated to a volume accessible by the host computer; sets a second-type virtual device including a second-type logical device, which is a virtual volume accessible by the host computer; and allocates each second first-type logical device, of the plurality of first-type logical devices, to a storage pool, wherein when the control unit receives first write data for the first first-type logical device included in the first-type virtual device, the control unit stores the first write data in the first first-type logical device, and when the control unit receives second write data for the second-type logical device included in the second-type virtual device, the control unit associates at least one second first-type logical device, of the first-type virtual device and allocated to the storage pool, with the second-type logical device, and stores the second write data in the second first-type logical device, wherein the storage system further comprises: a memory storing management information, which includes cache data to be destaged and configuration information regarding the configuration of the respective virtual devices, logical devices and volumes; and a non-volatile memory, wherein in response to the power of the storage system being turned off, the storage system: locates an unused area in the storage pool; assigns the unused portion as a system area; evacuates the management information stored in the memory to the system area; and stores in the non-volatile memory the address and size of the system area, wherein in response to the power of the storage system subsequently being turned back on, the storage system: consults the non-volatile memory to obtain information about the assigned system area where the management information is stored; reads the management information in the assigned system area; boots the system; and cancels the assignment of the unused area as a system area.