[Beowulf] Building a new cluster - seeking some advice

[Mark Hahn]

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

it's also worth realizing that disks are relatively reliable
if handled well, given some cool airflow, etc.  my organization
has been pleasantly surprised by the very low failure rate of 
sata disks in our clusters.  every compute node has 2x80G,
and we see a failure rate of maybe .5% annual (over 2-3 years 
of service).  in fact, we intended the 2 disks to be used in raid1,
but haven't bothered until recently - in retrospect, it probably
would have been better to get 1x160 or something.

using flash for node disks might also appeal for power savings,
but disks aren't actually that hot.  WD Caviar "green" disks are 
7.5W max, 4 idle, .3 standby.  if your IO is occasional enough to 
not wear out flash, I suspect you could safely auto-standby a disk.

-mark