Exabyte VXA-2 PacketLoader 1X10 1U

Simple Installation

At our Real-World Labs in Green Bay, Wis., I installed PacketLoader in combination with Dantz Retrospect Multi Server 6.5 backup software on a four-processor HP-Compaq DL580 Windows 2000 server. The PacketLoader model I evaluated included Exabyte's optional Ethernet-based remote-management package.

A SCSI cable problem made setup and configuration rough at first, but once that was solved, the connection process couldn't have been easier. The five-button panel and LCD display facilitated tape loading and other maintenance functions. It took less than an hour to install and configure the library, fill the changer with tapes and inventory them.

Many of the library's options were preset to usable configurations by default. In fact, the process that took the most time was attaching the necessary barcode labels to the various cartridges.

After I patched Retrospect to the most current drivers, the software had no difficulty identifying and interfacing with the PacketLoader library and its VXA-2 drive in their native modes. Exabyte wisely provided mode options that emulated the vendor's 210, EZ17 and AutoPak 1x10 libraries to accommodate backup software that might not support PacketLoader in native mode.

I had no problem defining a tape set and a 5-GB backup task for the library to run during lunchtime. Upon my return, Retrospect reported a perfectly executed backup--but to be sure, I restored the data to another location and compared volumes. The results were identical--performance was flawless.

Weekend Task

For the ultimate test, I backed up the 457-GB shared Archive folder over the weekend from our lab's main NAS (network-attached storage). Within three and a half days, I had another fine backup, with Retrospect reporting a respectable average of 97 MB per minute over the network.

Aside from its surprisingly low price, the PacketLoader's standout feature is the VXA-2 drive technology at its core. This second-generation, 8-mm, helical-scanning tape format is based on three proprietary data-recording innovations: Discrete Packet Format, Variable Speed Operation and Over Scan Operation. Unlike other streaming tape options that write data in long, uninterrupted blocks, a VXA-2 drive writes data in clusters of 128-KB packets that, when read, are reassembled in the VXA packet buffer and protected by four levels of Reed-Solomon error correction.

Keeping Data Safe

For additional data protection, PacketLoader features four overscanning read heads, which can read off-axis packets that tape damage might have otherwise rendered illegible. And by adjusting the drive's tape speed, you can match the host's data-transfer rate and eliminate backhitching--the rapid forward-and-backward tape-scanning process caused by read errors on restore, or by write errors resulting from data-stream loss during backups. This reduces read/record head wear, increases tape life to 500 uses and improves data throughput by eliminating wasted seek time.

VXA-2 is a logical replacement for the aging DDS/DAT tape format. What's more, it offers enough capacity to challenge the AIT-2 and DLT-1 tape formats--at a substantially lower hardware cost. From a performance standpoint, the VXA-2 tape drive's native data-transfer rate is 6 MB per second, which is double that of the DDS-4 and DLT-1, and equal to that of the AIT-2.

The PacketLoader's $2,499 list price includes one cleaning tape, mounting rails, barcode tape labels and an external SCSI cable and terminator. The street cost for Exabyte VXA tape media ranges from $35 for the V10 cartridge (40 GB native, 80 GB compressed) to $99 for the V23 cartridge (80 GB native, 160 GB compressed).For an additional $300, you can get Exabyte's remote-management Ethernet option, which provides convenient browser-based access to library status, but offers little in the way of active control.

The PacketLoader comes with a three-year limited warranty, which includes phone support weekdays from 6 a.m. to 6 p.m. Exabyte's Advanced Exchange Service Option will get you a refurbished replacement device within 24 hours when backed by a credit card.

Steven Hill owns and operates ToneCurve Technology, a digital imaging consulting company. Write to him at [email protected].

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