Can't Quite Kick the Tape Habit

BURLINGAME, Calif. -- StoragePlus -- While tape certainly isn't winning new fans for backup these days, even shops that embrace alternate technologies admit they still have tape libraries for archiving and disaster recovery.

Users on a disaster recovery panel at StoragePlus this week agreed tape remains a necessary evil in the data center.

"I think of tape as Hamburger Helper -- it's in the closet and you hope you don't need to use it," says David Webster, manager for IT architecture and strategy at Yahoo. (See Get Users Involved, Says Yahoo Boss.) "We live without tape for the bulk of our operations. Anybody who has to rely on tape in a crisis knows what it can be like watching that tape spin while hoping the data can be restored."

Yahoo has been using Sepaton virtual tape since March 2005, yet Webster still hasn't been able to pack away his tape libraries for good. He says achieving a state of tapelessness is an ongoing journey.

"We did not go into tapeless backups overnight, and we're still not there," he says. "VTL is a step towards that, and maybe eventually we'll stop calling it VTL. Hopefully we'll forget we even had to deal with libraries in the first place."Joe Egan, network analyst at Children's Central Hospital Central California, has the same attitude. "We've come to rely less on tape, Egan says. "We'll use tape as a last resort, but it's definitely being phased out.

Egan began phasing out tape when he embarked on a DR project two years ago for his electronic medical record system. Until then, he relied on tape for backups, but it took 46 hours for a full backup. There was no redundancy, it would take as much as seven days to restore a full system, and he could not test the recovery procedure. "We were just hoping it was going to come up," he says.

His current DR system uses a Xiotech 3D Edge 3000 SAN for primary data, and a second SAN in anther building. He uses disk copies of his Oracle database instead of snapshots by putting Oracle into hot backup mode, employing Xiotech's disk pause for a fast backup and then taking Oracle out of hot backup mode. He also added a secondary server for testing and recovery if the primary server fails.

Egan still has tape -- an ADIC Scalar 1000 and developed what he calls a serverless "copy disk to tape" method involving Symantec Net Backup Enterprise, Xiotech's SANScript and two Dell servers. He copies a raw disk image at block level, and duplicates 2.25 Tbytes of records to tape in less than 10 hours.

If he loses his primary data, Egan says he can recover within 10 minutes by connecting to his DR SAN. If he loses primary data and his primary server, it takes 20 minutes or less to recover by copying off his second server. And if he loses primary server and all disk copies, he can recover in less than 12 hours by connecting to the recovery server and restoring a tape image.Although he doesn't use VTL for his electronic records, Egan says he likes the technology. He does offer one caveat, though. If you're using VTL "try to do it in a different site [outside the data center]. You don't want to do it in the same site as your primary data because if you have a fire or flood, you've lost your backups. With tape you can keep the library in the same site, because you rotate tapes and take them off site."

Yahoo's Webster countered with another benefit of VTL. "If a tape drive dies on Friday night, we can restore off VTL and we're still meeting our SLAs," he says.

Dave Raffo, News Editor, Byte and Switch