A Hybrid Access Model for Storage Area Networks

Abstract

We present HSAN - a hybrid storage area network, which uses both in-band (like NFS) and out-of-band virtualization (like SAN FS) access models. Using hybrid servers that can serve as both metadata and NAS servers, HSAN intelligently decides the access model per each request, based on the characteristics of requested data. This hybrid model is implemented using low overhead cache-admission and cache-replacement schemes and aims to improve overall response times for a wide variety of workloads. Preliminary analysis of the hybrid model indicates performance improvements over both models.