[Beowulf] motherboards for diskless nodes

[Craig Tierney]

On Fri, 2005-02-25 at 01:16, John Hearns wrote:
> On Thu, 2005-02-24 at 18:20 -0500, Jamie Rollins wrote:
> > Hello.  I am new to this list, and to beowulfery in general.  I am working
> > at a physics lab and we have decided to put together a relatively small
> > beowulf cluster for doing data analysis.  I was wondering if people on
> > this list could answer a couple of my newbie questions.
> > 
> > The basic idea of the system is that it would be a collection of 16 to 32
> > off-the-shelf motherboards, all booting off the network and operating
> > completely disklessly.  We're looking at amd64 architecture running
> > Debian, although we're flexible (at least with the architecture ;).  Most
> > of my questions have to do with diskless operation.
> 
> Jamie, 
>   why are you going diskless?
> IDE hard drives cost very little, and you can still do your network
> install.
> Pick your favourite toolkit, Rocks, Oscar, Warewulf and away you go.
> 

IDE drives fail, they use power, you waste time cloning, and
depending on the toolkit you use you will run into problems
with image consistency.

I have run large systems of both kinds.  The last system was
diskless and I don't see myself going back.  I like changing
one file in one place and having the changes show up immediately.
I like installing a packing once, and having it show up immediately,
so I don't have to reclone or take the node offline to update
the image.

Craig


> 
> BTW, have a look at Clusterworld http://www.clusterworld.com
> They have a project for a low-cost cluster which is similar to your
> thoughts.
> 
> 
> Also, with the caveat that I work for a clustering company,
> why not look at a small turnkey cluster?
> I fully acknowledge that building a small cluster from scratch will be
> a good learning exercise, and you can get to grips with the motherboard,
> PXE etc. 
> However if you are spending a research grant, I'd argue that it would be
> cost effective to buy a system with support from any one of the
> companies that do this.
> If you get a prebuilt cluster, the company will have done the research
> on PXE booting, chosen gigabit interfaces and switches which perform
> well, chosen components which will last. And when your power supplies
> fail, or a disk fails someone will come round to replace them.
> And you can get on with doing your science.
>