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[Miscellaneous #RPI-761418]: want some help

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  • Subject: [Miscellaneous #RPI-761418]: want some help
  • Date: Mon, 03 Dec 2007 08:40:30 -0700
Hi Dipak Sahu,

One possible problem that can cause this is an AIX system not being
configured to write files larger than 2**30 bytes (that's 1073741824)
on an NFS-mounted file system.  Try writing a file slightly larger
than 2**30 bytes using nothing but system calls to open() and write()
and see if you get the error:

  write failed!: File too large

We have seen that on AIX, lseek() can return the wrong current
position in the file with no error indication just before a write()
error occurs, so we don't get the nice error message about "file too
large", just the assertion violation message.

Another possibility is that the assertion violation you are seeing
might be a result of having multiple threads in your application
sharing the same file descriptor for an open netCDF file.  The netCDF
library is not thread-safe, so if you want to write a file from
multiple threads, you should use the parallel netCDF library pnetcdf,
available from

  http://www-unix.mcs.anl.gov/parallel-netcdf/

or the version of parallel netCDF for I/O in the netCDF 4.0-beta release, which
is based on HDF5 parallel I/O.

--Russ

Russ Rew                                         UCAR Unidata Program
address@hidden                     http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: RPI-761418
Department: Support netCDF
Priority: Normal
Status: Closed