[Beowulf] ram disk - diskless nodes

[matt jones]

Mark Hahn wrote:

 > > shurely is cost effective as 512 of ram cost about 3 times as much
 > > as 512 of usb mem.
 >
 > you're right, I hadn't thought of it in those terms.  but it's still
 > per-node-installation, and therefore less scalable in many ways.
 > bear in mind that when people opt for diskful solutions, they usually
 > want big local storage for swap, /tmp, etc.  I claim that net booting
 > _and_ diskful is the right thing (just don't boot from the disk).
 > after all, vendors will often charge _extra_ for diskless nodes, since
 > their norm is diskful.  as part of a $1-4K node, evne a 160G disk
 > is just not a major concern.
 >
 > > and you could pull the usb 'keys' out to re configure or what not from
 > > other nodes that the admin can work from.
 >
 > you don't want to do that for even a 64-node cluster, let alone
 > hundreds...

didn't think of that. time costs alot more, and as you say for medium to 
large and giant clusters... removing and replacing x amount of usb keys 
would take longer and cost more than using the net to boot in the first 
place.

when you boot from net and then go to local storage, does the RAM used 
to boot stay off limits to the OS and programs or can it be used for 
other purposes once booting is done?

-- 
matt jones,