The Xyratex DataBlazer dockable hard drive

Reviewed by David Kilpatrick

Datablazer is a dockable hard disk cartridge designed to handle very large data files, like photo scans, which need to be repeatedly read or written on more than one host computer. Although fast fibre-optic networks are now appearing, central storage on a file-server is clumsy because the kind of programs which use these files, like Adobe Photoshop, hog the network not only during opens and saves but at unpredictable intervals during working.

The traditional answer has been sneakernet - you switch off a workstation, unplug one of the external hard disk drives, trot down to the next workstation where its files are needed, switch that one off, fit the disk, and re-boot.

Because of the SCSI interface used to connect most hard disk drives to current computers, unplugging 'live' is impossible. You can trash not only your files but the motherboard of the computer. So sneakernet is extremely tedious for all work larger than a removable disk cartridge.

Rewritable Winchester, mag-opt and floptical disks might seem to be an answer. The familiar old SyQuest 44 Mb disk has grown through an 88 Mb version to its current 200 Mb; the smaller 3.5 inch cousin is up to 270 Mb; the mag-opt 3.5" is now at 230 Mb and rising, and the new ZIP format and its rivals seem set to offer disks from 25 Mb to 1 Gb.

Given their low cost and postability you would expect these to be the solution. But they aren't. You wouldn't want to work on anything over a 10 Mb scan on SyQuest, and you would hesitate to open any size of file directly from a mag-opt, even a postage stamp sized 1 Mb TIFF. These drives are just much too slow.

You have to copy the file over to a faster-working hard disk. In the case of an full 230 mag-opt, you can go away and make coffee while it copies. Unerasable storage on CD-ROM is not much better; writing a 600 Mb CD-ROM on a dual-speed writer (about to drop below the three-figure price barrier) takes half an hour, and copying back off the CD five or ten minutes.

The solution

The ideal solution is a removable cartridge similar in capacity to a CD-ROM and fast enough to work on directly. System shutdowns and drive hookups would be gone for ever; file copying needed only once, or never if the scans were written directly to the cartridge and all work and output run from it. The disk could go from scanning station to retouching station, then to the designer's page make-up machine, and finally to the output department or bureau.

This solution almost exists - the Datablazer, produced by IBM spin-off Xyratex, does all this but uses a dockable hard drive rather than a cartridge. Docking stations are cheap at �150 each - more money can buy multi-drive docks, but we tested two single-slot versions which most photographic users would choose.

The cartridges start expensive for smallish and get very expensive for bigg-ish. We opted for two nominally 810 Mb each, in practice holding around 780 Mb of data. The total cost of our system of two docks and two cartridges was around �1,600 + VAT ($2,400).

This is expensive compared to sneakernet - shortly before we started this test a 730 Mb external hard disk, from Performance Direct, cost us under �250 ($400) and a full 1 Gb is now under �300 ($450) in the UK. For the same price as the Datablazer kit we could have five 1 Gb external disks, all usable simultaneously in any combination.

Practical tests

We undertook two projects using the Datablazers. The first was a large book with 113 colour and line art scans. Because the designer had not yet decided the layout, every picture was scanned to fit the page width of 170mm, directly to Datablazer from Leafscan 45 and Sharp JX600, via Photoshop. No performance degradation was noticed. Job done, the full disk was taken to the second dock where it was archived directly to DAT tape - far faster than archiving over the network, usually an overnight job.

When the layout was ready, the files were resized and corrected (freeing up half the disk) and the Quark XPress documents copied to the Datablazer. The operator took a dock home to completed the work. Later we were asked to produce a rush print-out, and the system came into its own - we just plugged the drive in and printed the files.

As I prepare this for WWW, the pages are being run off to final positive film, with over 550 A4 pages printed over three working days, including over 100 four-colour sets, the Datablazer has never once lost touch or thrown up a TIFF glitch. The output machine was a Mac Quadra 660AV running SCSI Manager 4.3.1, over Ethernet to an Appletalk box linking in to a Varityper (Tegra, Panther) 4990S imagesetter with a standard Speed Plus RIP running TransCal's HiLine 200-line screening at 1,200dpi.

This is now very antiquated imagesetting gear - tweaked 1988 RIP in a 1992 machine - but even so our pages were running at one every 35 seconds for text only, and around 2-3 minutes per color for separations with one or two pix per page. Without a very fast hard disk, you just can't achieve this speed.

The second project was an electronic studio shoot of several hundred pictures stored as 330Kb JPEG files. These were copied to the Datablazer, to be later decompressed, cropped and resaved as CMYK EPS files. Once again, working directly on the 'blazer cartridge was as fast as using a regular hard disk, and the cartridge was shuttled between the studio and the retouching station.

What we found out just before writing the Web update of this feature was that PageMaker 6.0, received for press review before our official upgrades (ordered weeks ago, still not here!), places RGB JPEGs and color separates directly from them using Kodak CMS. I ran a test and the separations were perfect. A half-page image was one-tenth of the size it would normally be. Using Mac LaserWriter Driver 8.3, the JPEG test was converted perfectly despite our only having a PostScript Level 1 RIP (Level 2 RIPs will interpret JPEG data directly, also reducing network traffic when printing, while Level 1 RIPs require the driver to interpret the JPEG for them - fortunately the Mac platform does all this without needing to be told, a minor benefit of the vintage 1984 bi-directional printer communication which I gather is just arriving with Windows '95 if you ask ever so nicely...). So, we won't need to convert the JPEGs. They can stay that way.

Hey ho, PageMaker 6.0 just rewrote the production flow for color book, magazine and newspaper publishing! Sadly, as half the world uses Quark XPress, no-one will ever be told and very few people will get excited about it - until the other side catches up, when it will be the subject of editorials in national newspapers, prime-time television, and massive advertising campaigns claiming a Universe First.

Any problems?

Here are the problems we encountered with our test Datablazers: first, the 'book' disk was dropped two feet on to a carpeted floor. All data was irrecoverable, and the disk had to be reformatted. We would not advise 'Datablazer by post' operation. We had our tape back-up, of course, to restore the drive.

Secondly, the keys used to unlock and insert/remove the cartridges got mixed up, and one set even got lost for a day; in our office the security of having different keys for each dock was of no value, just a nuisance.

Thirdly, 'hot-swapping' is specifically advised against in the Datablazer manual - they suggest powering down every time a cartridge is changed! This entirely negates the purpose of the system as you might as well just change ordinary SCSI drives this way. We found hot-swapping did no damage, but if we started up with the dock empty, the 'blazer might occasionally tell the Mac it had de-mounted itself, interrupting printing or another operation to produce an on-screen dialog, only to say 'the Datablazer is now remounted' the minute the �OK� box was clicked.

This was avoided by starting up the Mac with a cartridge in the dock and the key removed. Subsequent swaps seemed, then, to work reliably. However, since writing the magazine report, a further problem has appeared; if disk cacheing is set to 'on' using the supplied Spot-On version called RapidTrak (a disk driver), the Mac remembers the entire disk's directory in its cache, and insists that you still have the same hard disk remounted when you switch cartridges. It even brings up a complete desktop directory for the disk, and sees it with the wrong name. Needless to say, when THAT happens you get that disk the hell out of that dock as fast as you can - you don't hang around to see what goes if you actually try to click one of those imaginary file icons!

If Xyratex can address this glitch, and assure buyers that hot-swaps are safe, very large organisations will find Datablazer invaluable. No other system yet offers its features, though Micronet's DataDock arrives hard on its heels. The bounce-resistance of the drives could do with improving, as they need to survive motorcycle courier trips, but most of all the price needs attention.

The high cost is a result of using miniature hard drives intended for portables. A bigger cartridge containing a conventional 1" height mechanism would be perfectly acceptable. The 'unique selling point' is hot-swap docking, not small physical size. The main reason for needing hot-swap docking is not the trouble of powering a Mac/PC down and then up again, it's the problems created for users on the network who may be communicating with the server involved.

For anyone swapping drives or copying large files many times a day, Datablazer will solve problems fast. The UK installed user-base means that, like SyQuest, they got there first - and have established a new standard. How the system is faring in the USA I don't know, as it is physically manufactured in Britain. Any info from readers would be welcome.