Features - Enterprise Data Insights:

SAN VS. NAS -- ENDING STORAGE BIAS
By Geoff Barrall, CTO, BlueArc Corp

In 2000, when I first started visiting customers that were investigating new storage solutions, the storage world was polarized into two distinct camps: Network Attached Storage (NAS) and Storage Area Networks (SAN). I was surprised by the level of commitment each customer felt to a particular solution and the level of certainty as to why one solution was just right and the other could never work for their particular storage needs. It seemed as if the two solutions would never find common ground -- even the names for SAN and NAS were the exact reverse of the other.

Today, I find this bias to have almost completely disappeared. Customers are now insisting on solutions that offer the benefits of both NAS and SANs.

The question of whether one application's storage needs are met by SANs or NAS can be determined on an application-by-application basis, rather than on a SAN or NAS basis. In some cases, the same physical storage may even be shared for both file-level NAS and block-level SAN solutions (some iSCSI solutions do this today), delivering the benefits of storage consolidation and lowered management costs to the customer.

This polarization on the customer side is echoed by the storage vendors, which just a few years ago found their strategies in violent opposition. The storage panels I participate in at industry events were once a hotbed of SAN vs. NAS, Ethernet and Fibre Channel conflict; now it seems nearly all vendors agree on everything and are looking to move to a blended strategy.

For industry stalwarts like EMC, offering NAS systems in front of their SAN solution is nothing new, although an increased focus on their NAS products reflects an effort to provide an integrated solution. On the other hand, Network Appliance has moved from the NAS-only proposition held since the company's inception to their current offering, Fabric Attached Storage, which is capable of delivering both file and block services. Younger companies (such as my own company, BlueArc) have taken this a step further, opting for a mixed network storage approach offering hybrid SAN/NAS solutions from day one.

Another interesting commonality across the world of networked storage is that most vendors now offer disk storage based on both Fibre Channel and the cheaper, but lower performing, disk standard ATA or SATA. EMC offers these disks in SAN storage arrays and Network Appliance offers them in NAS-based systems. However, many newer companies have opted to offer them for either SAN or NAS access, allowing the customer to choose the most appropriate storage for their needs.

This trend of a divided storage community moving toward convergence continues in the evolution of the nearline backup market. Originally, networked tape-based devices were all SAN- or Fibre Channel-based. The new breed of nearline disk-based backup systems that has come to market over the last few years have predominantly been NAS- or file-based. More recently, vendors have begun to offer interfaces that emulate block-based tape or SAN systems. Once again, today's customers can choose to select a SAN or NAS approach to backup. In fact, most customers are now looking to a blended strategy mixing both types of storage in a short- and long-term backup strategy.

In the next few years, I expect that customer needs will increasingly come first and all vendors will close the gap to offer any disk type for any application behind either a SAN or NAS interface. The winners in the storage space market will be those vendors who provide flexible solutions and meet the majority of their customers' needs, regardless of the application or storage requirements.

Of course the real winner will be the customers themselves.

About Geoff Barrall

Geoff Barrall is the CTO, executive vice president and co-founder of BlueArc Corp and the principal architect of its core technology, the SiliconServer Architecture. Prior to joining BlueArc, Barrall founded four other ventures, including one of the first Fast Ethernet companies and a successful U.K. consultancy business. In this role, he was involved in the introduction of innovative networking products into U.K. markets, including the Packeteer and NetScout. Barrall received his Ph.D. in Cybernetics from the University of Reading in 1993.