HP, Quantum represent latest tape technology
Latest generations of LTO and SDLT prove speedy and capaciousFollow @infoworld
Seeing is believing, and nothing beats seeing with my own eyes how, for example, LTO3’s data-rate matching feature automatically speeds up or slows down the tape to adjust to the computer’s data flow. This approach ensures never having to stop a backup to reposition the tape. Indeed, as I looked through the cover, I saw that the tape was constantly winding or rewinding with a fluid motion, which is one of the reasons for its exceptional performance.
Like any other tape, an LTO3 tape cannot crunch data faster than the server delivers it. To provide proper transfer rate for the 960, HP also sent a ProLiant DL380 server with dual Ultra 320 SCSI controllers running Windows Server 2003. Attached to those controllers were four disk arrays, each hosting four LUNs (logical unit numbers) spread across seven drives. That configuration allowed me to run backups and restores over a maximum of 16 concurrent data streams, which created a data flow consistent with the capability of the tape.
To take advantage of those multiple streams, the server had installed on it HP OpenView Storage Data Protector, an application capable of running multiple concurrent backups to the same tape. For consistency, I used the same test bed for the Certance and Quantum devices.
That layout may seem like (and probably is) overkill for desktop tapes, but it’s important to understand that to really benefit from the additional speed these units provide, it may be necessary to pull data faster from your actual servers and storage devices.
The reward for putting together this test bed was immediately apparent. As I backed up 21GB of highly compressed data from a single LUN, I measured a transfer rate of just 68MBps.
Although this is the best speed the Quantum SDLT600 achieves, the HP tape does better. When I ran a concurrent backup of similarly compressible data from four volumes, the transfer rate jumped to almost 90MBps. Putting together streams from eight volumes pushed the transfer rate to 125MBps, whereas my best effort with a concurrent backup from 16 LUNs clocked in at more than 130MBps.
Consolidating data flows from multiple streams gets the best performance out of the LTO3, although your data might not compress as well as did my test files. Nevertheless, even at lower compression rates, the speed gap between the LTO3 and other tapes warrants a serious reassessment of your backup infrastructure. After all, it’s the fastest tape money can buy, and your business may need the reduced backup windows from using the HP Ultrium 960.
Certance CL 800
Last fall, prior to being purchased by Quantum, Certance was the first vendor to put an LTO3 drive on the market, and the company was equally quick to offer a bundle that includes a copy of the NetVault backup application by Bakbone, plus the convenient protection of a three-year warranty.
The desktop model of the CL 800 is a fraction of an inch wider and taller than the Quantum unit, but it’s slightly less deep. The front of the drive has a cartridge opening and a set of four LEDs to monitor power, activity, errors, and overall status of the drive.
Pushing a single button conveniently located on the right of the feeding slot will automatically load or unload the cartridge. By contrast, on the SDLT600 you have to manually push the cartridge inside the unit, although you use a button to eject it. As expected, all the other controls and connectors are located in the back of the unit.