[Beowulf] Old versions of Linux

[Donald Becker]

On Sun, 28 Oct 2007, Sandip Dev wrote:

> I am totally new to clustering. It seems most clustering software like
> OpenMosix need 2.4 kernel to work. Where can I get a older 2.4 kernel based
> Linux? Any ideas. Also does MPICH and OpenMPI require 2.4 kernel to run or
> do they run on 2.4? Also do these support 64 bit processors

It's still easy to download 2.4 based distributions, but you should make 
certain that's what you need.

If you are interested in performance, Mosix isn't the right place to 
start.  Transparent process migration results in considerable performance 
loss during I/O and communication.  This performance loss can be reduced 
by knowing about the migration, but then you've discarded the benefit of 
the "transparent" part, and should be using "directed" processes 
migration.

More directly on topic, the tradeoff between 2.4 and 2.6 is
  The 2.4 kernel performs better on small configurations, and most 
   2.4-based distributions are much more memory efficient.  This is
   important when running full installation on compute nodes with
   1GB or less memory
  The 2.6 kernel has a better scheduler when running many processes,
   especially on SMPs.  With the 2.4 kernel we got a significant
   performance advantage by running only compute processes on
   dedicated, lightweight compute nodes.  This eliminated the opportunity
   for the processes scheduler to make bad decisions.
   We still see an advantage with lightweight compute nodes using a 2.6
   kernel, but the O(1) scheduler and 8 core machines have eliminated the
   worst problems.  (Well, except that a few daemons on 
   workstation-oriented distributions are becoming Completely Evil  
  Device support.  This is the killer for using 2.4 on new machines.  Most
   new motherboards have devices that you'll need a 2.6 kernel for.  And
   not an old kernel, a pretty recent one.  


-- 
Donald Becker				becker at scyld.com
Penguin Computing / Scyld Software
www.penguincomputing.com		www.scyld.com
Annapolis MD and San Francisco CA