What Hardware ?

[Gavin McCullagh]

Hi,

On Wed, 09 May 2007, Michael wrote:

> Hi, sorry about that...
> Only about 5 to 7 workstations per server. I'm going to use the servers as
> 'workstations' aswell.

I'd imagine something fairly modest could deal with 5-7 workstations.  The
general experience (just as a data point) seems to be that a modern dual
xeon w 4 GB RAM can approach 40 concurrent users with regular applications.
If you really want to have two workstations, I guess it might be ideal to
get one which can handle at least 14 clients.  Then if one goes down you
can fail over to all machines on one server.

I guess you've decided to go with two servers over one for some good reason
but you might find it easier and even better just to use one beefier
machine that's not used as a workstation.  You won't need to organise
network authentication (ldap or nis), nfs, maintain software on two
machines, etc.  Up to you though of course.

==CPU==
Given how few users you'll have, dual cpu seems overkill.  A reasonably
quick modern cpu should be adequate.  In terms of compatibility, I'm a
little wary of AMD64 stuff still.  I'd be inclined either to buy a 32-bit
system or run 32-bit ubuntu on a 64-bit machine.

==RAM==
The general wisdom is to buy as much RAM as you can.  What the users don't
take up with applications will be used for readahead and caching, speeding
up the overall experience.

==Disks==
With lots of users, disk access can be an issue so try to buy quick ones
(scsi is ideal but sata should do -- bigger cache is good, so is faster
spin speed).  You probably want to put all the home directory storage on
one of the two servers and share it to the other.  I'd recommend
considering software RAID1 (ie 2 disks) on each server.  This will give you
greater fault tolerance.  If a disk fails, the machine can keep going on
one disk while you replace the other.

In terms of what hardware will work well with linux, broadly most stuff
does these days.  Driver problems tend to be more common with wireless
cards and printers than with core stuff like sound and network.  You
sometimes get issues with cutting edge video cards, but you can generally
fall back to using 2D or even the vesa driver which performs pretty fine
for most applications, particularly on high spec video cards.  At the
minute, I'm using vesa with a fancy dual head ATI card, mostly cause I
don't want to use a proprietary driver.

I'm not convinced of the stability of 64-bit stuff yet and certain
applications won't work (such as the adobe flash player) on 64-bit so I'd
be inclined to stick with 32-bit ubuntu unless you have good reason not to.
I'm not sure if using 64- or 32-bit hardware would make a difference.

Gavin