Patent ID: 8055631
Filing Date: 2011-11-08
Classification: G06F,Y10S

Abstract:
1. A computer program product comprising a computer usable medium having computer usable program instruction codes for reducing data loss and unavailability in a system having a storage hierarchy, said computer program product comprising: a set of instruction codes for receiving a read request for read data; a set of instruction codes for recognizing a data failure in a storage device in response to the read request; a set of instruction codes for determining if RAID protection can handle the data failure; a set of instruction codes for searching for a cached source of the read data in response to recognizing the data failure if said RAID protection can not handle the data failure; a set of instructions for writing the read data in cache back to the storage device in which a data failure occurred if the read data was found in cache; a set of instructions for determining if the read data containing the error has been allocated for storing; a set of instructions for writing a blank data block back to the device in which a data failure occurred if the read data containing the error has not been allocated; a set of instruction codes for retrieving the read data from a backup system if a cached source of the read data is unavailable; a set of instruction codes for determining if the read data has been updated since the last backup; a set of instructions for determining read data updates pertaining to the read data; and a set of instruction codes for rebuilding the read data utilizing a combination of the retrieved data updates and the data from the backup system.