diskless nodes? (was Re: Xbox clusters?)

[W Bauske]

Velocet wrote:
> 
> I'd go insane configuring things if I had disk-full nodes. Diskless node
> installations require me to run one cp -r command, sed 2 files with a new ip
> address and mac address and power the thing up - presto, node n+1 is online.

How big is that file tree you're copying?

> I wouldnt do with the headaches of having to install stuff on n disks.
> Been through that where n = 18, its a big pain. Not to mention that 5
> of the nodes were down for servicing when I had to do the work. Now
> I gotta schedule a context-switch to do the SAME wokr over again and
> recall how I did it for those nodes when they finally come back. If
> I had a node down on a diskless system they'd boot up with all the current
> changes.

Diskless is a bit simpler than disk-full but not alot.

Using RH kickstart, a disk-full node installs in around 10 minutes.
If one trimmed down the RPM's, it would probably be 5 minutes or less. 
I currently load around a GB for an image. I'd bet if I worked at it,
I could get a disk-full node to install in 3-4 minutes at which point,
it would look very similar to diskless. You just install everytime the
node reboots or comes up. I read somewhere about a university that
does exactly that and will install whatever OS you select at boot.

> 
> In fact, as jobs finish we reboot nodes just for the hell of it - clears
> memory leaks and loads all current configs, kernels, etc. Its just too
> sweet to avoid!
> 
> Does NO ONE use diskless clusters?
> 

I ran them around 8-10 years ago.

One thing I liked about diskless was I could edit the files that
controlled the node even if it wasn't running. Can be handy sometimes.

Of course, with kickstart, you add customizations in the kickstart
file and re-install so it's not so far off.

Wes