Stable memory for a disk write cache

Abstract

Lack of I/O performance is fast becoming a limiting factor in many computing systems. The yearly doubling of CPU speeds is not being matched by corresponding gains in I/O performance. This paper explores one aspect of the architecture of a high performance fault-tolerant cached RAID subsystem for a multiprocessor. The disk write cache is implemented as a memory-mapped stable memory. The features of a VRAM-based stable memory and its associated RAID controller are discussed.