Re: [ROOT] Using root with OpenMOSIX (fwd)

From: Andrej Kugler (kugler@ujf.cas.cz)
Date: Thu Jun 13 2002 - 13:44:15 MEST


Hi, colleagues, 

We got mail below from Ivana Hrivnacova. We had the same problem with
running "Root" on MOSIX-cluster (4 PC's with RedHat7.1). 
I assume, that if program is using routines in  shared memory, it will
introduce these segm.faults. It is mentioned in description of Mosix, if I
am not wrong. The Mosix Kernel reroutes only "system calls" to the "home"
machine, but calls to user routines just go unnoticed. And shared memory
did not migrate. ?????


						Andrej Kugler


> 
> ---------- Forwarded message ----------
> Date: Thu, 13 Jun 2002 09:56:35 +0200 (CEST)
> From: Ivana Hrivnacova <Ivana.Hrivnacova@cern.ch>
> To: Dagmar Adamova <adamova@ujf.cas.cz>
> Subject: Re: [ROOT] Using root with OpenMOSIX (fwd)
> 
> 
>  Tady je ten mail o MOSIXu,
> 
>  Ivana
> 
> ==============================================================
> e-mail:  Ivana.Hrivnacova@cern.ch
> address: Institut Physique Nucleaire, 91406 Orsay, France
> phone:   (33) 01 69 15 65 94
> ==============================================================
> 
> 
> ---------- Forwarded message ----------
> Date: 12 Jun 2002 16:22:54 +0200
> From: Fons Rademakers <Fons.Rademakers@cern.ch>
> To: Sam Waldman <waldman@HEP.Stanford.EDU>
> Cc: roottalk@pcroot.cern.ch
> Subject: Re: [ROOT] Using root with OpenMOSIX
> 
> Hi Sam,
> 
>   I assume Mosix correctly migrates all depending shared libs with the
> jobs? Any idea where it segv's?
> 
> Cheers, Fons.
> 
> 
> 
> On Tue, 2002-06-11 at 19:42, Sam Waldman wrote:
> > 
> > Hi folks,
> > 
> > 	I'm running ROOT on a 5 node redhat-7.3 cluster.  We have
> > installed an OpenMOSIX kernel on each of the machines,  allowing
> > transparent clustering across all 5 machines.  The makers of OpenMOSIX
> > call it "fork and forget",  and for many applications we run,  including
> > large geant applications,  it runs fine --  big jobs automatically migrate
> > around the cluster to the least loaded machine.  Unfortunately,  every
> > time mosix tries to send a root application to another machine,  it
> > segmentation faults.  If the job is locked onto one node,  even a node
> > seperate from the home node,  the job runs fine.
> > 
> > 	Does anyone have any experience using root with MOSIX or
> > OpenMOSIX?  Or are there any obvious reasons for this behaviour?  Any help
> > will be greatly appreciated.
> > 
> > 	sam waldman
> -- 
> Org:    CERN, European Laboratory for Particle Physics.
> Mail:   1211 Geneve 23, Switzerland
> E-Mail: Fons.Rademakers@cern.ch              Phone: +41 22 7679248
> WWW:    http://root.cern.ch/~rdm/            Fax:   +41 22 7679480
> 
> 

-------------------------------------------------------------------------------------------------
 Andrej Kugler, Nuclear Physics Institute, CZ 250 68  Rez, Czech Republic
 phone: +420-2-6617-3285          fax:+420-2-20941130   
 Email:kugler@ujf.cas.cz              +420-2-20940220
-------------------------------------------------------------------------------------------------



This archive was generated by hypermail 2b29 : Sat Jan 04 2003 - 23:50:56 MET