Micro Design International's SCSI Express 3.0 for Windows NT

Emedia Professional, April, 1998 by David Doering

Micro Design International's (MDI) SCSI Express is a familiar name in the Novell NetWare world. This dependable workhorse is now emerging as a significant enhancement to the limited services of Windows NT--both in the 3.51 and 4.0 flavors of the insurgent operating system. And an ever-wider range of hardware support makes SCSI Express a fearsome contender in the enterprise storage market.

One of the key benefits of SCSI Express 3.0 for Windows NT is that it does not require separate licenses to work with different kinds of storage hardware. For example, the same software handles both CD-ROM and other optical devices like MO and WORM drives--something that other networking software vendors require you to purchase separately.

As with the NetWare version, the NT version of SCSI Express performs ably with a surprising range of hardware. The list of supported devices includes MDI's own storage subsystems, which include both jukeboxes and towers. In addition, users will find such familiar names as Hewlett-Packard, NSM, Maxoptix, Pioneer, Panasonic, Cygnet, Pinnacle Micro, and Sony on the growing SCSI Express guest list.

SCSI Express also provides CD-ROM networking with single-drive-letter access to all CD-ROM titles. On the optical disc side, SCSI Express streamlines the access path by creating a single, contiguous NTFS volume of the multiple optical discs. Finally, it also provides a contemporary service by caching CD-ROM data from jukeboxes onto available hard disk space.

GETTING ON TRACK: DOCUMENTATION AND INSTALLATION

The new manual provided with SCSI Express 3.0 for NT improves immensely on earlier versions of MDI literature. For example, MDI has profusely illustrated the text with a screen shot or other graphic on almost every page. The text is also broken out into clearly defined sections and subsections. The material flows from introduction to installation and from getting started to managing different types of media. In the past, MDI's documentation has frequently proven difficult or unclear. But this year's manual beats its predecessors' documentation hands-down.

SCSI Express was tested on a Pentium 166Mhz PC running Windows NT with 32MB RAM and a 4GB hard drive. An HP C2988A SCSI 7-bay CD-ROM tower was used as the subsystem. The most difficult hurdle met in the installation process had nothing to do with SCSI Express itself. As most users of the system are aware, NT can get fairly finicky about hardware support. Efforts to get the server to recognize the Adaptec 1540 SCSI board and attached HP tower don't need to be discussed at length here, but such problems should be taken into account if you are starting from scratch by adding a storage subsystem.

For example, be aware that if you use Microsoft's Adaptec driver (version for AHA-154x/1640) you may have to upgrade your Adaptec SCSI board if you are attaching to a jukebox. The Microsoft driver software does not support the commands needed for juke-boxes on older AHA-154x, AHA-1640, AHA-154xB, and AHA-154xC boards. (Try Adaptec's driver instead.)

SCSI Express 3.0 works effectively with both Windows NT 3.51 and 4.0. If you plan on using it with NT 3.5 1, the manual suggests upgrading to the latest Service Pack prior to installing the SCSI Express software-something that should also be done with NT 4.0. Such a process is critical to success with installing system enhancement products like SCSI Express. Initially, the software will appear to work, but there can be unusual errors later on if the, system runs without the Service Packs installed.

The SCSI Express software itself includes the file system drivers, device drivers, and the management utilities and applications used by administrators and users. In essence, the SCSI Express software takes control of the server-attached devices from NT, a significant improvement over earlier editions and other products. For example, earlier versions of the NT software did not handle CD-ROM minichangers correctly, and would often get into a perpetual re-indexing loop that effectively took the devices offline.

CACHING AND METERING ON THE SCSI EXPRESS

MDI supplies specific instructions for running SCSI Express with cache partitions. Cache partitions are used with CD-ROM jukeboxes in order to accelerate access to CD-ROM data. These partitions must be set up on available hard disk space, and require a minimum of RAM in order to work. If system memory falls short, the dreaded NT blue screen appears and the system crashes. SCSI Express requires a minimum of 32MB for a cache partition of 1GB; larger partitions require 5MB RAM more for each 200MB increment. SCSI Express 3.0 is no different from other NT-based storage management applications in expecting generous amounts of RAM to be available on the server, so this requirement for caching is not unreasonable for a system supporting a jukebox, and a capacity level most active NT environments should already have.

The biggest change implemented in the NT version of SCSI Express is the revamped administrator utility. The product now includes a GUI tool, called Inspector, for media management that enables system administrators to create CD-ROM title groups, control the sharing of titles, lock or restrict access to specific titles or devices, and perform a range of system monitoring functions. Inspector also provides software metering, which sets a maximum number of users who can access a title simultaneously. The number is specified by the type of license purchased.