By Michele Hope
To read Part 1 of this series, click here.
July 24, 2006—Phil Jay, a senior network technician at the Gates Chili School District, in Rochester, NY, is quite happy with the 20:1 backup compression rates offered by his ExaGrid NAS-based InfiniteFiler system, which includes a SATA-based Intelligent Data Repository.
But what really gets him excited is not the compression. Jay used to spend as much as 45 minutes a day monitoring, managing, and troubleshooting the multiple backup jobs that had been scheduled to run the previous night. The staggered backup jobs were designed to protect data on the 14 servers that support the school district's administrative staff applications, as well as high school and middle school staff and students involved in creating large files for various art, graphics, and technical classes.
Jay's headaches involved managing local and remote tape rotations among the various servers, running between servers to view tape activity, and battling backup window overruns from the middle school and high school data that was starting to max out nightly tape backup capacities.
The ExaGrid system now frees him of these types of headaches. Jay applauds the unified console from which he can now view all disk and tape activity across all 14 servers. Instead of 45 minutes a day, he estimates he now spends two to three minutes at the console reading through logs. Since installing the ExaGrid system, he has moved completely away from the use of tape and estimates it will take the school district three to four years to recoup the cost of the ExaGrid system, based on yearly tape savings alone.
He now plans to deploy a second ExaGrid system for remote disaster recovery at one of the school district's elementary schools farthest removed from the main campus. "My primary site will do all the work. Then once it's done, we'll set up another job to take that information and send it out to my DR InfiniteFiler and Repository," says Jay. "At that point, there's really no need for tape at all."
Keep the tape
Some D2D users are not sold on the concept of disk replacing tape entirely and choose to use disk for backup in only specific instances.
For Travis McCulloch, systems engineer at Orlando-based Hilton Grand Vacations, situations lending themselves to disk-based backup include applications with short backup windows or rapid recovery needs, and remote office backups that traverse the WAN and benefit from the throughput speed of random disk access at the corporate data center.
McCulloch uses CommVault's Galaxy software for disk-based backup in these cases, with some disks and "a fast group of spindles" he's allotted from both an HP MSA1000 system and an EMC CX100. The Galaxy software offers both direct-to-disk backup functionality and VTL functionality to emulate a tape library. McCulloch appreciates how easy the system makes it to manage and restore backup data, without needing to send the file back to a "fake-tape" staging area first, like he had to do with a prior VTL solution.
One of McCulloch's main D2D uses is to support the backup needs of the company's remote offices in Las Vegas and Hawaii. Instead of backing up locally, Hilton Grand Vacations has chosen to centralize and encrypt remote backups by sending the backup data over the company's existing WAN link.
Here, Galaxy's disk-based backup functionality—and a Riverbed Technology Steelhead WAN accelerator sending only new or changed data—are in use to more quickly transmit the nightly data. Once the data set arrives at the primary data center, the Galaxy software then copies it to tape in a faster throughput stream than would be possible initial tape-based write operations. Data sets stored on disk are soon overwritten by new backup data, making the disk a short-term staging area for backups waiting to be offloaded to tape.
McCulloch figured he could only get about 1GB per hour of data transmitted to tape over his current WAN connection, and he'd end up with a lot of tape troubles in the bargain, from "shoeshining" to extra tape drive wear and tear. Instead of tying up one of his Orlando tape drives for 9 hours to get 10GB of data, McCulloch opted instead for disk backup. "It's much faster to run that to disk, and much easier on the equipment. Plus, when I back up that 10GB locally to tape, it only takes 10 minutes," McCulloch explains.
More disk staging
Another CommVault Galaxy user is Matt Pittman, director of enterprise systems at Penson Financial Services, an organization that handles much of the back-end work to clear transactions for brokerage houses. Pittman recently acquired two Xiotech Magnitude 3D 3000 disk arrays to help store primary data along with tackling both his data-protection and tiered storage agendas. One of the disk arrays is at the company's Dallas headquarters, while the other array is at an off-site disaster-recovery location.
Pittman knew how critical it was for the company to maintain access to Microsoft Exchange e-mail transactions at all times. He also knew his tape-based backup environment might require as much as a full day to restore the system in the event of an outage. He went looking for a disk-based solution that would let him recover Exchange from the point of an actual outage in just two to four hours.
He eventually went with a multi-pronged approach to data protection and data migration. Pittman now uses CommVault's Galaxy to perform local backups to a group of SATA drives in the Xiotech Magnitude array (the total chassis comprises 50% Fibre Channel disks and 50% SATA disks). The local backup data is then streamed directly to an LTO-3 tape drive, at which point it is overwritten daily on disk. To ensure rapid recovery, Pittman also uses Xiotech's DataScale Geo-Replication software to perform synchronous mirrors of data between the primary disk array and the secondary, off-site system.
This multi-pronged approach has led to a number of positive changes: Local backup times have been cut in half since the company switched from tape to disk-based backups. Pittman says the change now allows his group to do full backups of Exchange each night, as opposed to once a week. He also claims that they can restore Exchange in less than 10 minutes, if needed, including fail-over to remove servers—a feat well below his original goal of restoring the system in two to four hours.
Pittman has chosen to tackle the growing volume of backup data more proactively at Penson Financial Services via an emerging information lifecycle management (ILM) strategy that also incorporates Xiotech disk arrays, in conjunction with CommVault's Data Migrator software. He now uses this solution to identify and migrate certain e-mail from primary storage to SATA disks if it has not been accessed in a certain number of days. This helps him maintain a more manageable size for the overall production data requiring backup.
Michele Hope is a freelance storage writer. She can be reached at email@example.com