Sure, users say, tape still has a lower cost-per-gigabyte
These days, Revenue Science backs up its data using its BlueArc NAS arrays' snapshot capabilities and then replicates it to a remote data center in Seattle. Because the firm is taking point-in-time snapshots of the data, Weatherford doesn't worry too much about replicating corrupted data. For internal applications like Exchange, Revenue Science uses Avamar Technologies' Axion software to back up to a remote site.
For rural organizations, it's the shipping of tape that's problematic. "We're in a fairly remote area," says Todd Pittman, IT director at a bank in Chalen, Wash. The closest major metropolises (Seattle and Spokane) are both three hours away. "Finding a courier, the expense and worrying if; they made it was a pain in the neck," he says.
Three years ago, Pittman's firm began backing up 15 servers to a Unitrends disk-only Data Protection Unit (DPU) with a hot-swappable drive he would store at another facility in town. "But we were always getting dinged by auditors for not storing our backups far enough away," says Pittman. Last year, his firm upgraded to a new DPU 320 with 1.2 terabytes (TB) of capacity and bought the optional data vaulting license. Pittman's bank now sends its nightly backups over a pre-existing T1 line to a disaster recovery (DR) site 50 miles away "and the auditors are very pleased."
Pittman acknowledges that the cost was a bit more -- approximately $30,000 for the two identical DPU units vs. $20,000 per year for a tape solution -- but he likes the simplicity of the disk-vaulting approach. Bandwidth costs weren't an issue because the bank was already paying for a T1 line to its DR site.
Other users are taking a more gradual approach to tapeless backup. Rebecca Berg, systems administrator at Farm Credit Services of America (FCSA) in Omaha, Neb., is still doing daily full backups to tape, but is moving to daily incrementals to disk, plus a weekly offsite tape copy. With 10 tapes in the daily full rotation, "our tapes costs are astronomical," says Berg. Furthermore, backup to disk will reduce what the firm spends with Iron Mountain.
As it stands, Iron Mountain picks up tapes every day at 9:00 a.m., and brings them back if FCSA has to do a restore. "Every time they rush a tape, they charge us $75," says Berg. Doing incrementals to tape would mean even more Iron Mountain charges because doing an incremental restore requires all the tapes since the last full. Berg is also evaluating replication software from CommVault Systems and Topio in the hopes of eventually cutting tape out all together.
But so far, Iron Mountain hasn't seen a change in the amount of tape it transports, says Geoff Nesnow, program manager for data protection and recovery. "Users are getting more efficient with how they write data out to tape, but the rate of storage growth has balanced the savings," he says. Iron Mountain offers an electronic vaulting service with its LiveVault backup software to small- to medium-sized customers but, at the high end, "the fundamental economics of bandwidth don't make sense; tape makes sense," he says.
And while bandwidth costs are coming down, they're not coming down fast enough to accommodate the volume of backup data generated by a typical enterprise, says Frank Slootman, president and CEO at disk-based data protection startup Data Domain.
"When you reduce your data by 20, 30, 40 times, then it becomes possible to move that data over the wire," he says. Data Domain's DD400 family of appliances incorporates block-level, single-instancing technology to achieve that sort of data reduction. Last month, Data Domain also announced enhanced replication capabilities for its appliances that allow users to replicate subsets of their backup data, or set up peer-to-peer and many-to-one configurations.
This article originally appeared in the June 2006 issue of "Storage" magazine.