[Beowulf] Q: Cooling units? Raised floors? General machine room stuff..

[Robert G. Brown]

On Fri, 2 Jul 2004, Jim Lux wrote:

> >   Finally, what other suggestions do people have for equipment needed?
> > On my list we've got the UPS, the AC, thermal sensors and killswitches,
> > APC Masterswitch units, power lines, network lines, web/video camera and
> > an alarm.  Anything else people find useful?
> 
> Coat rack to hang some jackets on.

Work bench.  A nice one, with rechargable screwdriver and bit set,
various hand tools, good lighting, a network drop or three, a small KVM
and flatpanel video/keyboard, screw/part organized storage, a rack to
hang spare cables on -- you get the idea.  Even if you get top shelf
service agreements on everything, you WILL be working down there
prepping nodes to go in or out, replacing failed drives on out of
warranty systems, and so forth.

Comfortable swivel/rolling work chairs to match the bench, and if you
are really into comfort, put a cheap workstation on your bench KVM
(useful in and of itself) and add a nice set of headphones on a long
cable to keep your ears warm, exclude room noise (likely considerable),
and let you listen to that 20 GB ogg collection we know that you've got
squirrelled away somewhere while working...;-)  

A phone.  One with a really loud ringer or even a blinking light ringer,
if your AC is as loud as ours.

He says as he prepares to descend into the bowels of the physics
department to work in OUR cluster/server room... sigh.  Comfort is key.

> When thinking about UPSes, etc.  consider partitioning your system so that
> not everything dies together.  Your monitoring and head node computers might
> want a longer duration than the compute nodes.  (that web cam's not going to
> do much for you if the power is shut off...)
> 
> A temperature/humidity recorder is nice to have.  It could be as simple as
> an off the shelf weatherstation widget and a logging program.  It lets you
> better manage your HVAC.

Regarding AC units, there are some very lovely 10 ton and 15 ton units.
Since a major component of your cost will be space renovation, and since
this will become MORE costly later as it will require downtime and dust
on top of the mere dollars, you'll really want to TRY to engineer the
space now for its eventual future peak capacity.  You'd also much rather
have too much AC than two little.

You might want two 5 ton units instead of one 10, though -- that way you
have a bit of redundancy should one fail while you are still at current
levels.  I agree with Jim, though -- talk to your HVAC contractor, they
should be able to give you good advice here.

   rgb

-- 
Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu