NAS: No role or new role?

Networked-attached storage is viewed by some as the "old" way to share files among users working on different operating systems. NAS, they contend, is not well-suited to handling large files because of its dependence on the general-purpose TCP/IP network for file transport. That's why it will be swept away once file sharing on high-speed storage-area networks (SANs) come into its own, or so goes the argument.

However, that might not be the case. One current trend sees a merging of the two technologies — a marriage of the high-speed, high-volume performance of SANs at the back-end and the well-known ease of use of NAS at the front.

Another benefit comes from many users already having NAS systems in place, so expanding storage capabilities is that much easier because the existing infrastructure won't have to be taken out and applications replaced.

"The benefit of a NAS appliance in the past was that it was simple to attach and manage, but you couldn't get the same performance from it as direct-attached

or SAN-attached storage," said Ruth Columbo, a group line manager at Veritas Software. "But when you put [a NAS system] in front of storage provisioned from a SAN, it provides a lot of the availability, scalability and performance that has traditionally haunted the NAS environment."

Veritas' ServPoint NAS is one option for turning NAS into a gateway for SAN storage.

Market watcher the Yankee Group sees the network storage market, including both NAS and SAN, growing to more than $24 billion in 2005, from just $9.4 billion last year. The NAS portion of that will be slightly less than $9 billion in 2005.

Companies such as Compaq Computer Corp. — now part of Hewlett-Packard Co. — EMC Corp. and Network Appliance Inc. have all recently announced products that merge the functionality of NAS and SAN architectures. Upcoming next-generation NAS systems are expected to include integrated, distributed file systems and data management capabilities.

An advance expected to further bolster NAS is the use of the Direct Attached File System, a standard that improves both the speed and flexibility of NAS. Network Appliance recently announced the first storage product to use DAFS and claimed that its performance shows that a NAS

device attached to a local-area network can outperform a direct-attached storage system.