A Performance Comparison of NFS and iSCSI for IP-Networked Storage

IP-networked storage protocols such as NFS and iSCSI have become increasingly common in today's LAN environments. In this paper, we experimentally compare NFS and iSCSI performance for environments with no data sharing across machines. Our micro- and macro-benchmarking results on the Linux platform show that iSCSI and NFS are comparable for data-intensive workloads, while the former outperforms latter by a factor of two or more for meta-data intensive workloads. We identify aggressive meta-data caching and aggregation of meta-data updates in iSCSI to be the primary reasons for this performance difference and propose enhancements to NFS to overcome these limitations.