Disk-to-disk - D2D - backup has been embraced early by Overland Storage. Its Reo devices are disk backup targets that can be placed in between backup applications and its Neo tape libraries in a transparent fashion. They were introduced in August, 2003. Recently they have been extended with Overland's Multi-SitePAC software to bring remote sites into the D2D orbit.

Michael Kerman is a VP and chief strategy officer for Overland Storage. He says that Overland customers are buying lots of D2D product and, as a consequence, tape's function is changing: "Tape is evolving to an archiving role because of the switch to disk for backup. Customers want the fast restore (from disk). ... D2D makes a problem go away. That's what the user is interested in."

Another factor accelerating the transition to disk caches in front of tape libraries is data growth from the regulatory influence: "The compliance influence is causing 'good enough' backup processes to be no longer satisfactory."

With ILM (information Life Cycle Management) involving a data moving function from disk tier to disk tier and with Overland now having a data move function courtesy of D2D, is their any interest in Overland moving up the data protection stack?

"Moving forward up the (ILM) tiers is absolutely of interest to us. We don't provide data moving software - backup application - that's a primary storage area. We want to grow our tape space business and grow our secondary storage space. ... We want to ensure our disk and tape solutions have movement facilities between them - Reo and Neo integration."

He mentioned the idea of having lots of partners' applications. Kerman also said that software is of great interest to Overland: "Software for us is where the differentiation (from other suppliers) will occur. Hardware will just be the delivery platform."

Risk aversion
He also mentioned that the backup data protection process is well-understood and said: "Customers are a very risk-averse audience. The expectation is that you will play within their model," of backup applications and primary storage.

What about backing up the newer type of data known as content-addressed storage (CAS)?

"We've been talking to a number of backup vendors. They're ill-prepared but their presence is a given. Ultimately people are looking at CAS as a method to reduce how much is backed up." This refers to the de-duping property of CAS in which replicated data elements are stored once only.

"Backup applications will get CAS features and then they'll backup up CAS data to disk or tape. Step forward Overland. We want to be the preferred target."

Holographic storage adoption
What about optical disk as an alternative to tape?

"People like tape because of the file room. It's portable. It's physical. We believe the next generation of retention storage will have much the same properties. But it has to borrow some of disk; it has to be fast; it has to be random-access."

This doesn't mean holographic storage; that's off the wall: "Data is not just for Christmas; it's for life. Customers want something tried and tested." The dependable history of tape's development and in-format road maps are very compelling to risk-averse customers. Holographic storage has no history and no rock-solid dependability evidence of committment from its developers. Why should customers move away from tape? "

It would have to be a huge, compelling event to make people change to holographic disk and lose that backward compatibility. They'd have to run in parallel for a while."