Re: bombing out writing large scratch files

[Barry Smith <bsmith@xxxxxxxxxxx>]

  Randy,

    The only "PETSc" related reason for this is that
xvec(i), i=1,np is accessing out of range. What is xvec
and is it of length 1 to np?

   Barry


On Sat, 27 May 2006, Randall Mackie 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.