[Beowulf] Building a new cluster - seeking some advice

[Jeffrey B. Layton]

David Bakin wrote:
> Speaking of nodes w/ disks vs. nodes without - I was thinking of 
> equiping a small cluster (microwulf style) with each node having a 
> single USB thumbdrive instead of a disk.  I thought it might be easier 
> than trying to get nodes to boot PXE style over the network.  And it 
> seemed to me that thumbdrives might be easier than disk-per-node to 
> keep in sync: I'd just unplug them from the nodes, plug them into to a 
> USB hub on another computer where I build my distribution, and copy 
> files to them, then plug them back into their nodes.  Also the USB 
> drives would serve for any local filesystem needs, e.g., for logging 
> or whatever.  With a 1Gb key available for about $12 it seemed a 
> pretty easy and cheap and low power solution.  And no moving parts 
> means the "disks" won't die for mechanical reasons (and they won't be 
> written to enough to worry about flash-wear).
>  
> Does anyone have any thoughts on this?  Tried it?  Knows why it won't 
> work?

It should work fine. Just be sure you're not putting file systems on the 
thumb drives
that do lots of IO (/var/log, swap partitions) because of rewrite issues 
(you can
easily send the log information to the master node and perhaps you could 
put a
very small swap file on the thumb drive if you think you need it). There 
is work
afoot in the Linux kernel to allow real swapping over the network. It's 
not quite
there yet (the last I looked), but it does look like Linus will allow it 
once it's
reaches some level of maturity.

You could also try it with SD cards or whatever flash media you like.

Jeff