[K12OSN] 2-server setup

[Krsnendu dasa]

On 31/01/07, Burke Almquist <balmquist at mindfirestudios.com> wrote:
> 2. The needs of the file and authentication server are fundamentally
> different than that of an LTSP server.
>
>
> Leaving /home and LDAP on a separate machine (with fast SCSI RAID)
> lets you put all the expensive storage (and the important information
> that needs backup) on one machine. The NFS/LDAP servers need
> reliability and fast storage primarily, not speed, to do their job.
> That means SCSI RAID, maybe even hot swap and redundant power
> supplies.  Think main file server here.  Your NFS/LDAP server
> achieves reliability by building redundancy into the machine with
> RAID, a UPS, hot swap features, redundant power supplies, etc. This
> also makes scaling up easier. This machine scales up by adding RAM
> and disks (so start with SOME extra cpu, just not as much as a
> monster LTSP server maybe).
>
>
Would you recommend a different operating system for the LDAP /home
server? Perhaps a "more stable" distribution like Centos as opposed to
Fedora? And the machine can also be stripped down in the sense you
don't need openoffice and other enduser programs.

In our school we have 27 terminals and a couple windows laptops for
teachers. On the terminals we run Gnome and mostly use Openoffice or
Office XP. We also quite often use flash websites using Firefox.

We are on a tight budget, so I have tried to do the best I can at  low
cost. I have currently setup 2 k12ltsp servers on 2 identical desktop
machines. AMD 2500XP with 2GB RAM each. Each has a 120GB SATA hard
drive and gigabit network.
1:  RAID 1 Complete K12LTSP including hosting NFS /home
2: Complete K12LTSP on one drive and a second 250GB drive for BackupPC.

I now have a spare 1.2GHZ AMD computer. Would it be worth putting an
SATA2 raid card into that and hosting /home and LDAP there? How good
it SATA2 with NCQ? Or is it absolutely essential to go for (way more
expensive) SCSI hard drives?

How much CPU power would I need for an LDAP /home host for 27 clients?
Is 1.2 GHZ enough? And how much RAM? I know that BackupPC (rsync) uses
a bit of cpu power, but because this machine would back up at night I
guess it wouldn't matter much.

Thanks.
Krsnendu dasa