Patent ID: 8762648

Claim:
A storage system comprising: a storage apparatus to store data; first and second control apparatuses each including: a cache memory to cache the data in the storage apparatus, an access controller to make access to the storage apparatus by using the cache data in the cache memory in response to an access request from a host device, while managing the respective cache memories of the first and second control apparatuses such that each other's cache data is mirrored therein; a first reboot controller, disposed in the first control apparatus, which causes, upon detection that the access controller in the second control apparatus is stopped, the second control apparatus to reboot and places a boot event record in a non-volatile storage device of the second control apparatus to indicate that the rebooting of the second control apparatus has been caused by the first reboot controller; and a second reboot controller, disposed in the second control apparatus, which causes the first control apparatus to reboot while keeping intact the cache data stored in the cache memory of the first control apparatus, when the access controller of the first control apparatus is stopped while the second control apparatus is rebooted, and when the non-volatile storage device of the second control apparatus stores the boot event record indicating that the rebooting of the second control apparatus has been caused by the first reboot controller.