[K12OSN] New Building's LTSP Server

[Sean Harbour]

I agree with Les, use two fast but inexpensive desktop machines. Two hard drives per machine in a raid 1 would be preferable over one drive per machine.

You can have high performance and reliability. Plus, upgrades are easy, simply take one at a time offline for maintenance.

The simplest load balancing method is easy to implement. Plug both servers into the same client switch, and setup their DHCP scopes with the same subnet, but give Server A the low range, say, 64-128, and give server B the high range, say, 129-193. Least loaded server wins the client DHCP request every time, and no conflicts. If Server A goes down, affected clients reboot and are automatically picked up by Server B.

You can setup a third server class machine for the NFS homes so clients won't have two separate homes, but it's not strictly necessary depending on how and where the kids store documents. 

Thanks,

Sean Harbour
Senior Network Engineer
Northwest Regional Education Service District
Hillsboro, OR 97124
sharbour at nwresd.k12.or.us
503-614-1448

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Message: 8
Date: Thu, 05 May 2011 13:19:49 -0500
From: Les Mikesell <lesmikesell at gmail.com>
To: k12osn at redhat.com
Subject: Re: [K12OSN] New Building's LTSP Server
Message-ID: <4DC2EA45.4070907 at gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

On 5/5/2011 12:53 PM, Jeff Siddall wrote:
>
> A decent _new_ desktop system has more than 10X the performance, more
> than 10X the storage and likely 4X the RAM of that server.  Getting a
> server that can keep up with that performance will cost $$$ thousands.

An ltsp server is sort-of a special case where you need the CPU
performance because you are running the client desktops and apps (unless
you have local apps) and you also need disk reliability.  I think there
is a case for using an older, slower but sever-class (dual power
supplies, hardware raid, etc.) machine as an NFS and authentication
server with one or more fast desktop machines (lots of RAM but otherwise
cheap) acting as the ltsp servers - and being mostly interchangeable or
even disposable.

--
   Les Mikesell
    lesmikesell at gmail.com