Continuous backup gains traction

For continuous backup technology, also known as continuous data protection (CDP), 2004 is the year that vendors have moved from promises to actual products. Although the market is still small -- inhabited by startups such as Revivio, Mendocino Software, Alacritus and XOsoft -- the buzz is relatively loud.

"I do a lot of work with our customers, and I'm running into a lot of interest in the concept," said Stephen Foskett, director of strategy services for the CTO group at Glasshouse Technologies, an independent storage strategy and implementation services company in Framingham, Mass.

There are several approaches to continuous data protection, depending on the vendor, but in essence the software functions in a journaling capacity, said Robert Gray, research vice president of storage systems at International Data Corp., a research company in Framingham, Mass. "Fundamentally, it's a journaling type of system whereby they keep track of every single change," he said.

"CDP is like a continual rolling database of every single change made to the system it monitors, keeping a time-stamped record of all I/O. "It's really pretty clever," Foskett said. "It gives a level of protection you wouldn't get out of a conventional backup product." And it also promises near instantaneous recovery of data, pulled from just about any moment in time -- something traditional recovery methods cannot do.

Traditional tape backups are basically a once a day shot, points out Foskett, with a recovery point objective (RPO) window of 24 hours -- unacceptable to many users. Attempts to update that with hourly snapshots or replication brings the RPO up to about an hour, but that's still substantial for many enterprise-level production applications.

"It turns out that users don't want to lose any transactions, and the only way to do that is to have something that can capture every transaction implemented at the application level, which provides a continuous snapshot ability to roll back through time," said Foskett.

Moreover, recovery is nearly instantaneous, said Kirby Wadsworth, senior vice president of marketing and business development at Lexington, Mass.-based Revivio. "We give an exact virtual disk, and we do it instantly," he said. "It takes three or four seconds as opposed to tape."

CDP is also relatively low risk to install, since it doesn't need to be integrated into expensive SANs or tier one storage. Instead, CDP functions much like a video camera, running a steady picture of the bits streaming back and forth across the systems. "Even if we fail, the worst-case scenario is that you get an error message saying that the Revivio box is offline," Wadsworth said. "There's almost no risk to deployment."

In spite of the interest, the market is too new to be anything but tiny. "The whole market is certainly nothing like $100 million yet," Wadsworth said. The startups' products are all relatively new to the market, and as such, they have a long hill to climb to gain mainstream acceptance from Corporate America -- whose members prefer to buy technology from companies that are likely to remain viable long enough to support the products.

Wadsworth said that his company has sold to 'more than a handful' of customers, many in the financial services industry. He said he expects next year to be the breakout year. "This is the foundational year, the year we put a footprint in the marketplace," he said. "It will get interesting next year when people start posting revenue." He said he expects the market to hit that $100 million mark next year, with three or four players doing something in the $20 million to $25 million range.

John Wernke, vice president of marketing at Mendocino Software, has a slightly different take on the market. "Companies aren't testing the market so much as they are deploying CDP on an application by application basis," he said. "They have mission-critical applications that they can't afford a four-hour recovery time for. To protect that application, there are CDP solutions. It's not an infrastructure play right now."

CDP won't replace traditional backup and recovery technologies, but will serve as a supplemental option, Wernke said. "CDP is not a wholesale replacement for back up and replication," he said. "The strategy needs to be complementary and delivered in conjunction with existing backup technology."

"It's something certain applications and situations will be attracted to," Gray said. "For example, I can see CDP getting early traction in certain compliance situations."

Indeed, many of the big storage vendors, such as EMC and IBM, are expected to integrate CDP into their product lines over time. "The long-term trend is very favorable, but over time to the extent CDP gains traction, it will become a feature of general product lines," Gray said. As such, he predicts that the current vendors will either license their technologies or get acquired. 'It's not a long-term standalone business, in my opinion."

About the author: Carol Hildebrand is a freelance writer based in Wellesley, Mass.