Cheap one U servers?

Bruce M Simpson bms at spc.org
Wed Sep 25 11:22:13 BST 2002


On Tue, Sep 24, 2002 at 09:34:57PM +0100, Paul Civati wrote:
> What motherboard's are you using?

Right now I'm using a QDI Winnex 1 that I picked up for 25 quid at one of the
London computer fairs. This only takes a PPGA Celeron so it's a bit slow.
Some i810 boards can take FC-PGA. i815 boards generally can take FC-PGA.

Soon to be replaced with A/Open MX3S which has fxp onboard, hopefully.

1Ghz Celeries can be had for under 50 quid if you shop around, but these are
FC-PGA2 and I'm not sure if the i815 boards will take them (they have a
different core voltage, 1.475V, not 1.7V or 1.75V like the other FCs).

You can ditch the monitor after:-
 - setting up the BIOS
 - configuring 3wire.9600 on ttyd0 in /etc/ttys. You have to do this
   because if you have a simple 3 wire null modem cable, getty won't respond.
   If you're using a terminal server that supplies handshaking, you can
   probably get away with local instead of 3wire. I use 9600 baud purely for
   the sake of consistency. Some people like 38400 better.
 - setting 'set console comconsole' in /boot/loader.rc.
 - recompiling your kernel with 0x30 for sio0's flags, or just sticking
   the relevant incantation into /boot/kernel.conf.

I think these i815 boards would be *ideal* for building a low cost FreeBSD
cluster, simply because of their level of integration; they have hardware
RNG, they have fxp on-board, they have decent I/O north/southbridge 
performance, they have ATA-100, and a free PCI slot (counting the riser).

They even have watchdog timers and hardware monitoring (which I'll be
aiming to get working next - I want NMIs when things go wrong, and the
i815 has hardware watchdog timers built-in which FreeBSD doesn't currently
do anything with).

In an ideal world, I could completely manage these things from sio0, but
that is not to be.

> Did you have much trouble getting it all to fit?

The cables are a bit of a tight squeeze. Ideally I'd have really short
round cables. Don't even think about using ribbon cables unless they're
really short. I bought 45cm round IDE cables and cut the rubber cladding
around it to fit, after getting rid of the glands. This means you still
have airflow, and the cables still fit. Ribbons won't work unless *really
short* because of how they obstruct the airflow.

> I notice some motherboards designed for servers haved angled memory
> sockets, and you can also get low profile CPU coolers..

Acme sell the low profile fans for a very reasonable price. 8 pounds (ex
VAT) it says here on my invoice, for a Socket 370 1U Cooler up to 1Ghz.

It's possible to build these boxes on a budget of less than 500 UKP per unit,
and that isn't even buying in bulk. We shall see how well the fans do; the
main case fan is a bit noisy (there are 4 fans in total in the ACM-135,
counting the CPU and PSU fans).

BMS




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