US Patent 8386834 Raid storage configuration for cached data storage

A storage server receives a notification indicating a failure of a mass storage device in a storage array. The storage server determines whether a number of failures exceeds a fault tolerance level of the array and if the number of failures exceeds the fault tolerance level, recovers an address space corresponding to the failed storage device. When recovering the address space, the storage server replaces the failed storage device with a spare storage device having an identifiable pattern stored thereon and determines whether a file system on the storage system can automatically invalidate cached data blocks on the failed storage device.