Tandberg Data LTO-3 HH review

For mid-range backup, no other tape format has had such an impact as Ultrium LTO. In our exclusive review of HP's StorageWorks Ultrium 1840 (web ID: 120516), we saw the sheer speed LTO-4 is capable of and, in another exclusive, we now look at the latest half-height LTO-3 model from Tandberg Data.

As with each generation of LTO, you get the full-height models first, followed a year or so later by the half-height versions. The LTO-3 HH is one of the first to hit the market and is designed to slot neatly into a single 5.25in bay, making it ideal for local server backup. However, the demands of the autoloader market dictate this reduced height requirement just as much, as it allows them to offer greater capacities in a smaller rack chassis.

Unfortunately, the price the drive pays for being vertically challenged is a drop in performance. With the LTO-2 HH drive, native speed fell from 30MB/sec to 24MB/sec and with LTO-3 it falls from 85MB/sec to 60MB/sec. This may be nigh on a 30% drop, but it isn't as bad as it sounds, as few SMB servers are capable of achieving a sustained 85MB/sec throughput for local backup anyway. The model on review was supplied as a bare drive, but Tandberg Data also offers internal and external versions, complete with cables, media, cleaning cartridges and backup software. WORM also comes into the picture, as the drive utilises the flash memory chip built into the LTO-3 cartridges to stop any data being overwritten.

For performance and compatibility testing, we connected the drive to an Adaptec Ultra320 SCSI adapter in a Supermicro dual 3GHz Xeon 5160 server running Windows Server 2003 R2. For backup software, we used the A-Listed CA ARCserve 11.5 (web ID: 78869), and the drive was asked to back up and restore an 8GB mixture of test data representing a typical departmental server. ARCserve returned some top results, reporting 65.4MB/sec for backup and 40MB/sec for restoration. Note that to achieve these speeds we secured data from a separate RAID0 striped array comprising a quartet of Seagate Cheetah 15K.4 SAS hard disks. To show how important it is to get your setup correct, we ran the same backup test on the server's system disk and saw performance drop to 30MB/sec.

LTO is now in the enviable position of having no serious competition for tape-based mid-range data backup. As we reported a couple of months ago, Quantum advised us that it had suspended development of SDLT, which is as good as saying it's going end-of-life. Furthermore, as SMB server capacities increase exponentially, LTO is looking a top choice at this level as no other format can offer such a solid product roadmap, with LTO-4 already available and two more generations still to come.

The LTO-3 HH is an inevitable evolution for LTO-3, making it even more versatile and allowing it to be offered as an internal backup solution with new servers and to give LTO autoloaders a big boost in capacity. The smaller height does introduce a drop in native performance, but 60MB/sec is certainly nothing to sniff at, and our tests show that this is achievable with the right hardware.

Author: Dave Mitchell