Will Dyson on Wed, 10 Sep 2003 01:09:05 -0400

[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]

Re: [PLUG] diskless linux

On Tue, 2003-09-09 at 19:20, Alex Birch wrote:
> Jano,


> > I understand linux requires a physical space for memory swapping even with
> > a large memory bank (2 Gb).  Can this be avoided?
> Depends on the size of the problem. If you compile your own kernel,
> especially for a cluster you can get it down to < 1 MB.
> This can be avoided by never using all of the physical ram.

I'm not sure what the size of the kernel image has to do with the need
for swap. Kernel memory is unswapable, its true. But the size of the
kernel image on disk is not linearly related to how much memory the
kernel uses. Just like the size of a regular binary doesn't tell you how
much ram it is going to use for its data structures.

At any rate, many people run swapless systems without a problem. Swap is
only really useful for swapping out idle programs. Its been a while
since I managed a cluster, but ideally a cluster node should be running
a single job at a time (and maybe a small monitoring daemon). Right?

Will Dyson
"Back off man, I'm a scientist!" -Dr. Peter Venkman

Philadelphia Linux Users Group        --       http://www.phillylinux.org
Announcements - http://lists.netisland.net/mailman/listinfo/plug-announce
General Discussion  --   http://lists.netisland.net/mailman/listinfo/plug