Using Linux in a Training Environment
Our original prototype training room uses a stock 60MHz Pentium processor in its host machine, although newer training rooms are coming on-line with Pentium 90MHz processors or better. There is a huge difference in processing speed between the older Pentium 60 models and the newer Pentium 90 units, although I have had great success with both systems. If you are still hesitant about obtaining a Pentium machine, a 486DX/100 unit will provide comparable performance.
For most training classes including X Windows and Motif, 16MB is adequate. Of course, greater performance can be obtained by simply upgrading to 32MB of RAM on the host. I recommend getting the full 32MB of RAM initially, rather than purchasing it later. While our MIS department has been quite accommodating to our hardware requests, your organization may not be as generous. If you have corporate red tape to cut through, request the 32MB up front.
We currently use the Adaptec 1542CF SCSI controllers. These are ISA-based cards which have been stable under Linux for quite some time. I have experimented with the Adaptec 2940 PCI-based controller, but it was a bit too squirrelly for my tastes. Even though the 1542 units are 16-bit ISA cards, my aim was stability first and foremost. A few other cards which I can personally attest to are the Future Domain 1680 series and the older Always IN-2000 cards.
Our first training room used an older 500MB IDE drive. While it served admirably and reliably, it also reached maximum capacity in a hurry. For a full install of Linux, complete with XFree86, I allow a liberal 200MB or so. However, some other storage requirements must be taken into consideration during the planning phase. For instance:
Motif—With the newer X11R6 distributions of SWiM, roughly 30MB of storage is needed for a full install from CD.
Student lab work—Plenty of storage must be set aside for student lab work. Some courses, such as the Shell Programming course, don't require much storage for student lab work. Other courses, like our X/Motif Development course, require quite a bit. For 8 students, I recommend having around 20MB or so available per student for their course work.
Linux kernels—If you plan on experimenting with newer revisions of the Linux kernel, plan on having a lot of extra room. I recommend having 20MB or so per revision.
Temporary storage—Plan on setting aside a liberal amount of storage for temporary files (i.e., the /tmp directory). In fact, I recommend that you make this directory a separate file system altogether. I like to have 100-200MB available for a typical temporary storage area.
WWW storage—We run an internal training Web, complete with on-line prep tests for our students. I must point out that even the smallest working Web requires a good bit of storage. We currently have around 20MB or so of web information on-line (including the web server software and our image library).
Working storage—Of course, we need plenty of room to sock away on-line course materials (completed solutions to lab work, shell scripts, etc). In addition, our instructors do quite a bit of development and experimentation as well, so that must be taken into account as well. A few hundred megabytes will work nicely.
Of course, any good Linux system needs a CD-ROM unit attached. With most software packages shipping on CD-ROM these days (including Linux), it pays to have one of these drives in place. Should disaster strike, it's much easier to reload the base operating system from CD-ROM, rather than a tape backup unit. I have had great success with several models from NEC, Sony and Sanyo. Try to stay away from proprietary SCSI interfaces, such as come with some Compaq CD-ROM drives. That old single-spin, wonder unit in the attic may make a perfect candidate for this job, since it won't be used all the time.
These wonderful devices make perfect solutions for backups. These drives are so fast and quiet that I have actually performed system backups while a class was in session. Any major brand should work nicely, although I can personally attest to the 2GB and 4GB models from Colorado. Even if you have to perform backups on an older 120/250MB Colorado Jumbo, the issue of system and working backups should be addressed swiftly and immediately.
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