De-Dupers Demand Disk Mindset

When ADIC acquired Rocksoft this week, it picked up a backup technology that early adopters rate highly for efficiency. (See ADIC in De-Dupe Deal.) But some aren't sure a tape vendor will put it to best use.

ADIC spent $63 million on Rocksoft's de-duplication technology, which it will integrate into its disk products. ADIC's core business is tape libraries, but it has joined other tape vendors in adding disk to its product line in recent years.

Meanwhile, Symantec is expected to launch de-duplication software from technology Veritas acquired by buying DataCenter Technologies (DCT) last year before Symantec gobbled up Veritas. (See Veritas Archives Another Startup.)

Industry analysts expect other backup software vendors to follow suit.

"If that capability is not built into any [backup] product in the next 18 months, that vendor will suffer," says analyst Arun Taneja of the Taneja Group.The key to de-duplication is to transmit only data that has changed since the last backup. Essentially, there are two kinds: Backup software applications such as Avamar and Asigra do the de-duplication before writing to the storage system. Hardware systems such as Diligent Technologies' virtual tape library (VTL) and Data Domain's compression appliances de-duplicate while writing to the storage system.

Users are eyeing both kinds of de-duplication, but some are chary about where they'll obtain it. Senior systems engineer Steve Merkel, of Web-hosting service provider Data393, looked at both types last year when he considered Avamar and Data Domain. Both startups were created as an alternative to tape backups, although they grudgingly admit tape will stick around for archiving.

Merkel liked that they didnt come from the tape world. His firm wasn't doing traditional tape backup, and he had no intention of going in that direction.

"Do we want 20-year old technology, or one that does it better faster, cheaper, and works exceptionally well?" he asks.

He picked Avamar Axion software because it compresses data before sending it across T1 lines from customer sites. He says an average backup includes less than 1 percent of new data, with that going up to 5 percent when backing up databases.The de-duplication software "allows us to do a significant amount of data protection across smaller WAN links," he says. "We wanted to protect our customers' data even if they did not have gear in our facility."

Merkel admits he might have gone in another direction if he were using tape along with disk backup.

"If you're backing up to tape, Data Domain makes perfect sense because you're going to reduce your media on the back end. You've already spent that much on backup software, you don't want to forklift. We were starting from scratch with a clean sheet of paper, so I didn't have to worry about a forklift."

Network administrator Lance Jeffrey of Idaho Central Credit Union agrees. He says he reduced his backup time from 48 hours with tape to less than 10 hours using a pair of Data Domain DD430 boxes with VTL capabilities. (See Data Domain Adds VTL Option.) He still archives data to tape with CommVault Galaxy software.

"We wanted to archive long-term storage to tape, but keep two month worth of data on disk for easy access," he says.He says he didn't evaluate other de-duplication software, but checked out an REO VTL from Overland Storage. As with ADIC, Overland is a traditional tape vendor moving into disk backup.

"We decided on Data Domain because of its replication capabilities, and its ability to act like disk," Jeffrey says. "REO wanted to look like disk, and act like a library. We felt it was old technology and they were stuck in the tape mindset. Data Domain is a disk and it acts like a disk."

— Dave Raffo, Senior Editor, Byte and Switch

Organizations mentioned in this article: