pCFS vs. PVFS: Comparing a Highly-Available Symmetrical Parallel Cluster File System with an Asymmetrical Parallel File System

pCFS is a highly available parallel, symmetrical (where nodes perform both compute and I/O work) cluster file system that we have designed to run in medium-sized clusters. In this paper, using exactly the same hardware and Linux version across all nodes we compare pCFS with two distinct configurations of PVFS: one using internal disks, and therefore not able to provide any tolerance against disk and/or I/O node failures, and another where PVFS I/O servers access LUNs in a disk array and thus provide high availability (in the following named HA-PVFS). We start by measuring I/O bandwidth and CPU consumption of PVFS and HA-PVFS setups; then, the same set of tests is performed with pCFS. We conclude that, when using the same hardware, pCFS compares very favourably with HA-PVFS, offering the same or higher I/O bandwidths at a much lower CPU consumption.