Five hot -- and cool -- storage technologies

Storage Virtualization

Yes, it's the "V" word, but we're not talking about server virtualization, which has dominated tech headlines this year. Storage virtualization - managing a number of storage resources such as storage area networks as a single pool and presenting to the user as a single resource - has been slow to take off in Canada, partly because of the smaller number of large enterprise operations compared to the US.

But when VMware launched VMware Infrastructure 3 with support for an iSCSI SAN, that made the storage virtualization pitch more compelling for the midsized enterprise, says John Sloan, senior research analyst with Canada-based Info-Tech Research Group. Many midsized companies would have direct attached storage on their servers, and would be sitting on the fence about consolidating and making a big investment in Fibre Channel, Sloan says. But now, as the server refresh window opens, companies are considering the more famous Baldwin brother. "This is where the pitch for server virtualization comes in," Sloan says. And in order to get the best out of a virtualized production environment, "they really need to abstract the storage from the server." Ironically, storage virtualization, which once had only large enterprise appeal, is more attractive to midsized businesses which don't have an existing investment in Fibre Channel to write off.

Cloud Storage

"Cloud" is a 2008 buzzword to rival the "V" word above. On the storage side, everyone from IBM to EMC to Microsoft has weighed in with a strategy or offering regarding storing data in the server cloud.

This trend, though, may be more sizzle than steak.

"The idea of hosting all your applications and files 'in the cloud' and using a thin client as your main means of access to them will never take off," argues Jon Stokes, senior editor and co-founder of Ars Technica. "I store quite a bit of data in my IMAP inbox via attachments, and I can access most of those files on my iPhone. So that's a form of cloud-plus-thin client computing, I suppose. But I'm not going to work an eight-hour day that way."

Though Ontario's privacy commissioner has been probing the security and privacy aspects of the cloud, Stokes says latency is the bigger challenge. There's an unchangeable inverse relationship between latency and cost per bit, and the cloud doesn't change that.

"Computer designers always place the maximum amount of the lowest-latency storage that they can afford as close to the ALUs as they can get it," he says. "Economics dictate that that maximum amount is never really enough to do everything you want to do, so they have to back that low-latency storage pool up with a larger, cheaper, higher-latency pool. And then they back the new pool up with an even larger pool, and so on until you get very far away from the ALUs."

Most of our work takes place in the layers of that hierarchy that are closest to the processor: the computer's hard disk, out to file servers on the local area network and the data centre. The cloud just provides more cheap, high-latency storage much further down in the hierarchy.