Performance Comparison of IP-Networked Storage

Dramatically increasing amounts of digital data are placing huge requirements on storage systems. IP-networked storage systems, such as the network file system (NFS)-based network-attached storage (NAS) systems and the iSCSI-storage area network (SAN) systems, have become increasingly common in today's local area network (LAN) environments. The emergence of new storage techniques, such as object-based storage (OBS) and content aware storage (CAS), significantly improves the functionality of storage devices to meet further needs for storage sub-systems. However, these may impact system performance. This paper compares the performance of NFS, iSCSI storage, object-based storage devices (OSDs), and CAS-based storage systems in an environment with no data sharing across host machines. A gigabit ethernet network is used as the storage network. Test results demonstrate that the performances of these systems are comparable with CAS being much better than the others for write operations. The performance bottlenecks in these systems are analyzed to provide insight into how future storage systems may be improved and possible optimization methods. The analysis shows how the I/O interfaces in these systems affect the application performance and that network-based storage systems require optimized I/O latency and reduced network and buffer processing in the servers.