Host-based RAID-5 and NV-RAM integration

Claim 1

In a computer having a processor, an input/output device, a system memory, a backup power supply for supplying power to the computing system, and a storage device configured as a RAID disk array, an apparatus for storing data to the storage device, said apparatus comprising: a memory cache storing data, said memory cache resident in the system memory of the computing system; a checkpoint module detecting a fault in the computing system and generating a fault indication; a cache manager operable between a first mode and a second mode, in said first mode said cache manager writing data and parity to said memory cache for temporary storage prior to writing said data and parity to said storage device, and in said second mode said cache manager writing data and parity to a temporary location in said storage device for temporary storage prior to writing said data and parity to said storage device; in response to the fault indication, said checkpoint module switching said cache manager from the first mode to the second mode.

Claim 4

A method for writing new data and new parity in a computing system having a system memory, and an array of drives arranged in a RAID configuration, the method comprising the computer implemented steps of: providing a backup power module for supplying power to the computing system in the event of a power disturbance; providing a cache in the system memory for storing parity and data information; calculating the new parity and new data from old parity and old data stored in the computing system; transferring the new data to the cache for storage therein; transferring the new parity to the cache for storage therein at a first location within said cache; writing the new data to the disk; writing the new parity to the cache at a second location within said cache; invalidating the new parity at the first location and new data stored in the cache, and detecting if the cache should be disabled based on an operating condition of the computing system.

Claim 5

A method for writing new data and new parity in a computing system having a system memory, and an array of drives arranged in a RAID configuration, the method comprising the computer implemented steps of: providing a backup power module for supplying power to the computing system in the event of a power disturbance; providing a cache in the system memory for storing parity and data information; calculating the new parity and new data from old parity and old data stored in the computing system; transferring the new data to the cache for storage therein; transferring the new parity to the cache for storage therein at a first location within said cache; writing the new data to the disk; writing the new parity to the cache at a second location within said cache; invalidating the new parity at the first location and new data stored in the cache, and detecting if the cache should be disabled based on an operating condition of the computing system.