Hello Gus: On Mon, Jul 12, 2010 at 03:02:40PM -0400, Gus Correa wrote: > Hi Doug > > Consider disk for: > > A) swap space (say, if the user programs are large, > or you can't buy a lot of RAM, etc); > I wonder if swapping over NFS would be efficient for HPC. > Disk may be a simple and cost effective solution.
We have bought enough RAM (6 GB /core) that will I hope prevent swapping. > B) input/output data files that your application programs may require > (if they already work in stagein-stageout mode, Now there you have me. What is stagein-stageout? > or if they do I/O so often that a NFS mounted file system > may get overwhelmed, hence reading/writing on local disk may be preferred). I am hoping to do that - write to local disk. Each node has a 1 TB disk, which I would like to split between the OS and user space. How to do that is still an unsolved problem at this point. The head node will have (6) 2 TB disks. > C) Would diskless scaling be a real big advantage for > a small/medium size cluster, say up to ~200 nodes? Good question. The node count is 16 (not 124, as I said previously - brain fart - 124 is the core count), and seems to me just over the border of what can be easily maintained as separate, diskful installs. Our one user has expressed a preference for "refreshing" the nodes before a job runs. By that, he means re-install the operating system. > E) booting when the NFS root server is not reachable > > Disks don't prevent one to keep a single image and distribute > it consistently across nodes, do they? I like that idea. > I guess there are old threads about this in the list archives. I looked in the beowulf archives, and only found very old (+years) articles. Is there another archive I should be looking at? > Just some thoughts. Much appreciated, Douglas. -- Douglas Guptill voice: 902-461-9749 Research Assistant, LSC 4640 email: douglas.gupt...@dal.ca Oceanography Department fax: 902-494-3877 Dalhousie University Halifax, NS, B3H 4J1, Canada _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
