Hardware Today: NAS and SANs Page 2
SANs and NAS Working Together
SAN comfort certainly explains the vendor's less cautious leap into gateway NAS, where NAS appliances act as file-based gatekeepers to block-based SAN networks. "Gateway NAS," said EMC's Joyce, "is great for NAS consolidation, where you've got a thousand NAS appliances stuck under desks all over the place, and want to get to a mode where you've managing the file serving capability the same way you're dealing with the block storage capability." Simply put, a NAS presents a SAN as a NAS to clients better equipped to interface with a NAS, for example, over IP.
The blurring between NAS and SAN is welcome for EMC, whose main NAS customers to date have been those who already "own EMC gear and love EMC gear" according to Gartner's Passmore. EMC has long targeted the extreme high end with its Celerra clusters and has, over the last few years, brought advanced capabilities such as high availability to the mid-tier table, blurring the distinctions between high-end and mid-tier.
NAS Thinks Small
With early NAS offerings targeting the mid-size and larger enterprise, EMC has recently turned its focus towards the lower-end storage market, perhaps aiming for a space typically owned by scrappy NAS competitor Snap Appliance, which Gartner Dataquest shows leading this market in units shipped. "You buy one of these things, you plug it into your network and turn it on, and, wow, you have a file server," said Passmore.
Mark Pollard, vice president of marketing and business development at Snap, said he sees his company's built-in Linux operating system as another differentiator. "By owning its operating systems, Snap Appliance can make any changes required to enable a new capability or feature," he said. "A great example of that is the embedded anti-virus which was introduced over a year ago ... this would have been impossible if Snap Appliance did not own its operating system."
The other player of note in the NAS market is Microsoft, which, while gaining roughly 20 percent of the market for NAS to date, according to Gartner, doesn't offer a true NAS option. "What it is, is a special CD with an installation wizard that makes it a little easier to start up Windows as a file server," Passmore said, "but once it's up and running, it's still Windows you know, the same old, same old."
With the distinction between NAS and SAN blurrier by the day, a more important distinction may be the protocol(s) you're going to use with your NAS/SAN mix: IP, Fibre Channel, or iSCSI.
How to choose among those options depends on your enterprise. "If your application doesn't do very much I/O, or if your server has lots of excess CPU cycles, then the IP network is going to perform very well for you, and you're going to be a happy camper," Passmore said. In that case, you'd want to deploy a traditional IP-based NAS.
"If, on the other hand, you're pushing your CPU like mad, and you've been using SCSI or Fibre Channel based storage, but you're thinking about going to IP-based storage because you've heard all the wonderful hype about how cheap it is, you're in serious trouble." If you fall into this category, you'll want to avoid the processor-intensive IP-based NAS and instead choose a Fiber Channel NAS or SAN.