NEC T16A2 Tape Library review

Tape drives may be having a tough time as users move to hard-disk-based backup but libraries still win hands down for their excellent price/capacity ratio. The T16A2 is a prime example: the LTO-4 version of this 16-slot library costs £4,399 and offers a massive 12.8TB native storage capacity.

Originally launched with a SCSI interface, the latest version of the T16A2 comes with a 3Gbits/sec SAS interface. It can't be faulted for build quality and this slim 2U chassis can be desk- or rack-mounted. Some vendors offer scalable licensing schemes where you license magazines and slots as required, but the T16A2 includes all 16 slots.

The chassis incorporates an eight-slot magazine on each side, with the half-height IBM LTO-4 drive mounted at the rear. A backlit LCD operator panel and keypad in the centre provides full access for manual configuration and it can also be used to view slot contents, unload and load cartridges, and move them around the magazines and drive.

The T16A2 also offers remote management and, although the web interface is somewhat simplistic, it provides plenty of operational information. A graphical view of the library and magazines shows which slots are populated, and selecting a component reveals its status.

The interface also provides access to the same features, so you can remotely initiate cleaning cycles from selected slots, move cartridges around the library, and load and unload the tape drive. The robotics can be placed online or offline, diagnostics run on the library and drive, and new firmware can be downloaded to the robot or the tape drive.

For testing we used a Boston Supermicro dual 3GHz Xeon 5160 server running Windows Server 2008 and called up Symantec Backup Exec 12.5 and the A-Listed ARCserve Backup 12.5 (see A List, p32). In both cases, the T16A2 was correctly identified and we had no problems with either product: both afforded us full access to all slots, where we could initiate inventories, catalogue tapes, move them around the cartridges and unload them.

We ran a full backup of 17GB of test data on the host server from a volume on a single SATA hard disk and saw top average speeds of around 65MB/sec - around half the speed the LTO-4 drive is capable of. As we've mentioned before, to get even close to the top performance from an LTO-4 tape drive you're going to need a very special host system.

When we reviewed the HP Ultrium 1840 we were able to achieve over 100MB/sec only by backing up from 2Gbits/sec fibre channel disk arrays. Clearly, most SMEs are unlikely to have this kind of setup so their main reason for choosing LTO-4 will be for its high capacity, not its performance.

As an SMB tape library NEC's T16A2 hits the spot nicely. Its web management interface could be more sophisticated and there are no further expansion capabilities, but it offers a high storage capacity at a low price, and it's greener than disk arrays too, with our power meter recording an average consumption of only 32W.

Author: Dave Mitchell