[K12OSN] Pentium 166 mHz Machines as Clients?
Terrell Prude', Jr.
microman at cmosnetworks.com
Sat May 8 14:25:24 UTC 2004
Dennis Daniels wrote:
>> There was a comment about the hard disks being useless. If you have
>> the thin clients booting from floppies, then that's true.
>> HOWEVER...floppies have a way of disappearing, so I've cat'ed the
>> Rom-O-Matic floppy image onto the hard disk, just like you would to a
>> floppy. Works great! Of course, you can't boot the Windows 98 that
>> was on those computers anymore, but like I care. :-D
>>
>> --TP
>
>
> What about drivers for older monitors... would that work as well? It
> would be fantabulous to find an easy way to load the all NIC drivers
> and monitor drivers /sound cards onto the hard-drives of these
> 'fat-clients'. We've been using NFS installs but a micro-boot
> installer for K12LTSP that would install the drivers needed for the
> local hardware onto the local machine...something automatic? :)
>
> Roughly speaking, I've spent over 100 hours getting 30 nodes running
> with the help of a linux/hardware enthusiast; 200 man hours spent
> trying to get random NICs and monitors to work on an entirely donated
> classroom network.
>
> When I tell teachers on campus they could do the same thing they say,
> "No way! I know how much time you've put in there getting it to work."
> And they're right, with donated equipment getting a network to run is
> a bear. Unless you're a nut or fanatic most would give up trying to
> get LTSP up and running on donated machines.
>
> A plea from a teacher in the treches: make it easier to get older
> machines, random NICS and ancient monitors into use as clients is a
> good thing for schools; something that Aunt Tilly the Teacher, and I,
> can use. ;)
>
> best
> dennis
OK, you got it. Note: I am emphatically *not* talking about fat
clients here. I mean thin clients. You'll see here in a minute.
1.) You need a supported NIC, i. e. something for which you can
download the .lzdsk from www.rom-o-matic.net. I happen to use 3Com
3C905's, but RealTek 8129-based cards also work great and are $8 in the USA.
2.) You need a supported video card. Any of the old S3 Trio64 boards,
S3 ViRGE, ATI 3D Rage Pro boards, etc. work very well; I use all three.
3.) You need enough DRAM. My experience says that 32MB works very
well, be it an x86 or PowerMac thin client. 16MB aren't enough.
4.) You need a supported CPU. On the x86 side, anything from an
80486-33 and up works. Using a Pentium is like using a Ferrari to go
the local grocery store (you don't need that kind of power, but you've
got braggin' rights, bay-bee!).
5.) If you want sound, you'll need a supported sound card. I find that
the old SoundBlaster 16 cards work great (we have a lot of those).
6.) If you want to boot your thin client from the hard disk, you'll of
course need a hard disk. For this purpose, a 10MB hard disk is already
much more than you need (yes, I said 10MB), so one of those old 540MB or
850MB hard disks will certainly work.
OK, now we have our box that we want to make into a thin client. You'll
want a blank floppy. With this floppy, we're going to make a standard
EtherBoot "boot floppy." Since my thin clients happen to use 3Com 3C905
cards of various vintages (the original, the B, and the C), I issue this
command:
[microman at localhost ltsp]$ su root
Password:
[root at localhost ltsp]# cat eb-5.0.11-3c905c-tpo.lzdsk > /dev/fd0
[root at localhost ltsp]#
Yes, the EtherBoot image for the 3C905C also works on the 3C905B and the
original 3C905. :-)
OK, now we have a boot floppy. Why'd we do this? We need to make sure
our thin client's going to work, so why not try it the "standard" way,
first, i. e. booting it with a boot floppy? :-) If things don't work,
then there's a problem that needs to be troubleshot with the standard
techniques (is the K12LTSP server actually running, is everything
plugged in and seated right, etc.). Once you've gotten your thin client
to successfully boot to K12LTSP from that boot floppy, then we're ready
for the next step. This same EtherBoot floppy can, of course, be used
for any other thin client with the same type of NIC.
Now we've verified that our thin client actually works. This is Good.
So, how do we get the thing to boot from the hard disk? We do it the
same way we get the thing to boot from our Rom-O-Matic floppy. You know
how we get the EtherBoot image onto the floppy? Well, we do exactly the
same thing to a hard disk. To do that, we need a command prompt on the
thin client itself. Just reboot the thin client with something like
Knoppix in command-prompt-only mode, so now you have a bash prompt. If
you don't have Knoppix, or if it takes too long for you to download
Knoppix, then you can use Damn Small Linux, available at
http://www.damnsmalllinux.org; it's only 55MB. If you don't have a
CD-ROM drive in your thin client, not to worry. Use tomsrtbt, which is
a floppy-based distro that runs in "8 meg to boot, more to unpack", so
it'll fit fine in 32MB. Tomsrtbt is available at http://www.toms.net/rb/.
OK, now we have our bash prompt on our thin client. So far, so good.
Now we have to actually get the Rom-O-Matic boot image onto the hard
disk. How? Easy. On that thin client, pop in that EtherBoot floppy
and type this:
[root at knoppixbox root]# cat /dev/fd0 > /dev/hda
and sit back and watch the entire contents of that floppy disk get
copied, bit for bit, onto the hard disk, starting with sector 0,0,1.
Essentially, you've made your hard disk into an "EtherBoot hard disk."
It acts just like a really big (and, of course, much faster) EtherBoot
floppy! This does have the side effect of wiping the MBR and partition
table that was originally on the hard disk, so you're not going to be
booting that Windows installation anymore, be it on NTFS, FAT, HPFS, or
whatever. But, again, like we care, since we want to get away from
Windows anyway. :-)
BTW, the other way to do this is by taking a second FAT-formatted
floppy, copying the .lzdsk file onto this second floppy (not
cat'ing--copying, as in the "cp" command or the GUI equivalent), popping
that floppy into your thin client, mounting that floppy, and doing this:
[root at knoppixbox root]# cat /mnt/floppy/eb-5.0.11-3c905c-tpo.lzdsk >
/dev/hda
Once that copying's done, reboot your thin client, and it'll come up
with a K12LTSP prompt faster than you've ever seen it before.
Now, there was a question about "drivers" for monitors. Monitors don't
use device drivers; video boards do. Thus, there is no "driver" for a
monitor any more than there is for a keyboard. Note that X11 will
automagically detect your thin client's video board when you fire it up,
so you don't have to be concerned with the video driver...provided, of
course, that it's supported by XFree86. :-) Most are, so this
shouldn't be an issue.
There are two concerns to have with "ancient" monitors:
1.) Can the monitor run at a resolution that will make the K12LTSP
desktop enjoyable to use?
2.) Is the dot pitch sufficiently small enough that it won't kill the
users' eyeballs? I remember those 0.39 dot-pitch screens all too well,
and I would never put a child in front of such a screen.
What you want to do is make sure that you're running at a resolution of
at least 800x600x16 on your thin clients. I don't know a video board
made since 1996 that would have trouble with that. My thin clients run
at 1024x768x24, and this is with 17" CRT monitors. Decent 15" monitors
will work at 800x600, but.... My advice would be, if you don't have
monitors that are capable of 1024x768, are 17", and have a 0.27 dot
pitch or less, that you go ahead and pick some up. They can be had for
$50 apiece, and you will be helping to preserve the health of eyeballs
by doing so. We all have tight budgets, but please don't visit 0.39 dot
pitch on your kids. Really.
Now that things are up and running, sit back and enjoy. For those
critics that told you "no way" because you spent all those hours with
donated "random" hardware, well, you'd have to do that anyway if you
were running Windows on them, too. That's an issue with random
hardware, not so much the operating system that you're running on it
(GNU/Linux supports *lots* of hardware). Furthermore, you can take
satisfaction in the fact that all those hours that you spent, you won't
have to do that again when the next Windows virus/worm comes out. You
now have only one box to maintain--the K12LTSP server--instead of 30.
My K12LTSP lab was entirely unaffected by Sasser, for example, so it is
time well spent doing this. The biggest issue, I've found, is the NIC.
Keep those consistent if at all possible. Again, I've seen cards based
on the RealTek 8129 chip for $8 in stores, and they are definitely
K12LTSP-friendly.
--TP
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