Patent ID: 6571324
Filing Date: 2003-05-27
Classification: G06F,G11C

Abstract:
A warmswap method for recovering full operation of a mirrored-write disk cache system, the cache system having at least a first and a second memory module and a writeback cache operation mode, the cache storing data to be written to at least one disk drive and metadata, the method used when one memory module of the first and second memory modules fails, the method comprising the steps of:disabling mirrored write operations in the cache system such that the cache system performs write operations only to a non-failed memory module of the first and second memory modules; replacing the memory module which has failed with a replacement memory module while continuing to perform the write operations to the non-failed memory module; testing the replacement memory module in the cache system to confirm correct operation of the replacement memory module; stopping write operations to the cache system; determining a subset of data that comprises data that has not been written to the at least one disk drive and located in the non-failed memory module; restoring the mirrored data in the cache system by copying the metadata, and the subset of data that comprises data that has not been written to the at least one disk drive, from the non-failed memory module to the replacement memory module; resuming write operations to the cache system; and re-enabling mirrored write operations in the cache system.