[lug] Specing out a server

[Sean Reifschneider]

On Tue, Jul 18, 2006 at 12:32:16PM -0400, Gordon Golding wrote:
>For 100 Users - this is definitely big enough.
>But what about 1000 or 5000 concurrent users?

This is not something that anyone but you can answer.  Zan points out the
standard thins to do for trying to plan capacity.  I'll add a few comments
to that.

In general, start out small.  Some would call it "lean".  This is pretty
common wisdom when starting a business, but it definitely applies to
scaling computers.  The system you've speced out above something around a
grand.  It's pretty easy to push that up to 2 or 5 grand if you start
beefing it up.  When you need the horsepower, the $5k system is going to
have more power than it does today.

Todays $1k server is tomorrows $750 server.  But, todays $5k server is
tomorrows $1k server.  We have a client that around 18 months ago bought a
$15k HP server.  Now on ebay you can get that class of server for around a
grand.

I see it all the time with our hosting clients.  We have clients who have
us spec large systems for them, based on 1 to 2 year projections of use,
and then they end up sitting idle for a year.

Another benefit of buying power later is that it allows you to do a lessons
learned when deploying the new box, and potentially fix any mistakes you
made on the first one.

Of course, the idea is that you buy more horsepower just before you need
it, not just after.  This is called "Capacity Analysis and Planning".
Learn it, live it, love it.

Right now is a particularly bad time to be buying lots of power because in
the next couple of months I expect the Core 2 Duo and C2D-based Xeons to be
out and commonly available, which will give you way more horsepower on the
system, with way less power consumption.  And the pricing is looking pretty
good.  Not sure what things are looking like for you, but for us P4 class
hardware is pretty tough as far as power consumption (and cooling) go.  May
not be a concern of ours, but we're definitely looking forward to the C2D
type systems.  I expect to begin trialing them within the next month or two
and probably switching over entirely to them a month or two after that for
new deployments.

I know a lot of people liked Opterons because of power consumption, but the
trials I did didn't show that dramatic overall system power consumption
drop, maybe 25%.  With Core Duo, I'm seeing more like half.  And without
the issues I've had with the Opterons...

Sean
-- 
 Sure I like country music, and I like violins.
 But right now I need a telecaster through a vibrolux turned up to ten.
Sean Reifschneider, Member of Technical Staff <jafo at tummy.com>
tummy.com, ltd. - Linux Consulting since 1995: Ask me about High Availability