Re: Mosix and traditional Beowulf software together (was Re: Mosix bundle)

[seregon <seregon@xxxxxxxxxxxxxxx>]

Rumor has it that Kragen Sitaker might have once said:
> Brad asks:
> > I am making a pitch for building a Beowulf, and I am wondering if I should
> > mention Mosix.  From my cursory look at their WWW page, it seemed that if
> > you were using Mosix on a cluster, it would not be possible to also use
> > MPI/PVM and other packages that treat the cluster as a big set of machines.
> > 
> > I would like to have both Mosix and traditional MPI/PVM applications at the
> > same time.  I think this would be a big sell to the faculty at my
> > University.  Can anyone comment on the feasibility of doing this and what the
> > caveats would be?
> 
> >From my understanding of MOSIX, you can definitely treat a MOSIX
> cluster as a group of separate machines.  But if you're not careful,
> your jobs may get migrated to other nodes, which may not be a win.
> MOSIX has a syscall (in Linux, apparently a /proc entry) that lets you
> flag a particular process as "not to be migrated".
> 
> I haven't downloaded MOSIX yet.  If I am lucky, I will have the
> opportunity to play with installing it on some cluster and playing with
> it.
> 
> -- 
> <kragen@xxxxxxxxx>       Kragen Sitaker     <http://www.pobox.com/~kragen/>
> TurboLinux is outselling NT in Japan's retail software market 10 to 1,
> so I hear. 
> -- http://www.performancecomputing.com/opinions/unixriot/981218.shtml

I have installed MOSIX on a small cluster (P90 + 2x Dual P233MMX).  I just got
it running so about all I have done is some stuff with povray.  I started
running the benchmark (skyvase) on the P90 and started a second benchmark on
one of the P233 boxes.   Mosix decided that the P90's povray would run faster
on the other P233 (I hadn't tied down the processes)...and it sure did.  There
was about at 10~15 second difference in the render times (with the migrated
process being the slower one).  So, far I haven't  seen MOSIX try to pick up
and move any of my pvmds or any of the processes spawned by pmvpov, but I
think that I have the loading balanced reasonably well in my configuration.  I
haven't added MOSIX to my dual P400 that can participate in the cluster yet,
but it would be interesting to see if any migration occurs with pvmpov if this
box is available.

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seregon@xxxxxxxxxxxxxxx               From wonder into wonder, existance opens
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