Memory on Scyld systems

Art Edwards edwards at
Thu Dec 6 22:26:44 PST 2001

On Tue, Nov 06, 2001 at 11:16:36AM -0500, Sean Dilda wrote:
> On Mon, 05 Nov 2001, Art Edwards wrote:
> > I have a question about memory on AMD-based clusters. I am now running
> > a homogeneous Scyld cluster with 768MB on each node. I have modified the 
> > config file with a mem= command and have had no problems. Now I am augmenting 
> > the cluster with new nodes that have 1.5 GB of memory on each node (single 
> > processor nodes). Is there a way to use a different config file for the new 
> > nodes? 
> The kernel commandline is stored in the bootfile /var/beowulf/boot.img
> By default, this image is sent to all nodes, but if the file
> /var/beowulf/boot.img.<nodenumber>  (ie boot.img.0) exists, it will use
> that image for the given node.  You can create this image by modifying
> /etc/beowulf/config.boot, then running
> beoboot -2 -n -o /var/beowulf/boot.img.<nodenumber>
> Once you've created one copy of the new bootfile, you should be able to
> symlink or hardlink the other filenames to it so that
> boot.img.<nodenumber> for all your new nodes points to it.
> Just remember, whenever you change anything with your bootfiles in the
> future, you're going to have to remake both files.
Thanks very much for this information. I have used it with some success. My only
problem is that when I issue

bpsh 13 free

I get

             total       used       free     shared    buffers     cached
Mem:        970524     805244     165280     446604     152084     131916
-/+ buffers/cache:     521244     449280
Swap:      2097136       6508    2090628

It seems that the system sees only 970M of 1.5 G. At boot time all
memory seems to be present. Is this a kernel issue?

Art Edwards

Arthur H. Edwards
712 Valencia Dr. NE
Abq. NM 87108

(505) 256-0834

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