turning off file locking

[Richard Hedges]

>Hello, I have been having off and on problems with file locking on NFS when
>using pnetcdf. The error i get is:
>
>File locking failed in ADIOI_Set_lock. If the file system is NFS, you need
>to use NFS version 3 and mount the directory with the 'noac' option (no
>attribute caching).
>
>My question is: is there anyway turn off file locking for the pnetcdf file?
>
>Thanks,
>James


Well, I think that the complaint is that the file locking in NFS is 
not adequate for the parallel operations that you are attempting. 
Things you can do:

1) use a real parallel filesystem (GPFS, CPFS, PVFS, Lustre: not NFS)
2) if an SMP node is big enough, use a local filesystem on an SMP node.
3) mount NFS without attribute caching (as recommended in the 
diagnostic message)

- Richard

-- 



====================================================

Richard Hedges
Scalable I/O Project
Development Environment Group - Livermore Computing
Lawrence Livermore National Laboratory
7000 East Avenue, MS L-550
Livermore, CA	94551

v:	(925) 423-2699
f:	(925) 423-1173
E:	richard-hedges at llnl.gov