bombing out writing large scratch files

[Matthew Knepley]

1) Make sure ssh is forwarding X (-Y I think)

2) -start_in_debugger

3) -display <your machine>:0.0

should do it.

   Matt

On 5/27/06, Randall Mackie <randy at geosystem.us> wrote:
>
> This is a stupid question, but how do I start in the debugger if I'm
> running
> on a cluster half-way around the world and I'm working on that cluster
> via ssh?
>
> Randy
>
>
> Matthew Knepley wrote:
> > The best thing to do here is get a stack trace from the debugger. From
> the
> > description, it is hard to tell what statement is trying to access which
> > illegal
> > memory.
> >
> >    Matt
> >
> > On 5/27/06, *Randall Mackie* <randy at geosystem.us
> > <mailto:randy at geosystem.us>> wrote:
> >
> >     In my PETSc based modeling code, I write out intermediate results to
> >     a scratch
> >     file, and then read them back later. This has worked fine up until
> >     today,
> >     when for a large model, this seems to be causing my program to crash
> >     with
> >     errors like:
> >
> >
> ------------------------------------------------------------------------
> >     [9]PETSC ERROR: Caught signal number 11 SEGV: Segmentation
> >     Violation, probably memory access out of range
> >
> >
> >     I've tracked down the offending code to:
> >
> >                IF (rank == 0) THEN
> >                  irec=(iper-1)*2+ipol
> >                  write(7,rec=irec) (xvec(i),i=1,np)
> >                END IF
> >
> >     It writes out xvec for the first record, but then on the second
> >     record my program is crashing.
> >
> >     The record length (from an inquire statement) is  recl     22626552
> >
> >     The size of the scratch file when my program crashes is 98M.
> >
> >     PETSc is compiled using the intel compilers ( v9.0 for fortran),
> >     and the users manual says that you can have record lengths of
> >     up to 2 billion bytes.
> >
> >     I'm kind of stuck as to what might be the cause. Any ideas from
> anyone
> >     would be greatly appreciated.
> >
> >     Randy Mackie
> >
> >     ps. I've tried both the optimized and debugging versions of the
> PETSc
> >     libraries, with the same result.
> >
> >
> >     --
> >     Randall Mackie
> >     GSY-USA, Inc.
> >     PMB# 643
> >     2261 Market St.,
> >     San Francisco, CA 94114-1600
> >     Tel (415) 469-8649
> >     Fax (415) 469-5044
> >
> >     California Registered Geophysicist
> >     License No. GP 1034
> >
> >
> >
> >
> > --
> > "Failure has a thousand explanations. Success doesn't need one" -- Sir
> > Alec Guiness
>
> --
> Randall Mackie
> GSY-USA, Inc.
> PMB# 643
> 2261 Market St.,
> San Francisco, CA 94114-1600
> Tel (415) 469-8649
> Fax (415) 469-5044
>
> California Registered Geophysicist
> License No. GP 1034
>
>


-- 
"Failure has a thousand explanations. Success doesn't need one" -- Sir Alec
Guiness
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