For what it's worth, I found the following from running ROMIO's tests with OMPIO on Lustre mounted without flock (or localflock). I used 48 processes on two nodes with Lustre for tests which don't require a specific number.
OMPIO fails tests atomicity, misc, and error on ext4; it additionally fails noncontig_coll2, fp, shared_fp, and ordered_fp on Lustre/noflock. On Lustre/noflock, ROMIO fails on atomicity, i_noncontig, noncontig, shared_fp, ordered_fp, and error. Please can OMPIO be changed to fail in the same way as ROMIO (with a clear message) for the operations it can't support without flock. Otherwise it looks as if you can potentially get invalid data, or at least waste time debugging other errors. I'd debug the common failure on the "error" test, but ptrace is disabled on the system. In case anyone else is in the same boat and can't get mounts changed, I suggested staging data to and from a PVFS2^WOrangeFS ephemeral filesystem on jobs' TMPDIR local mounts if they will fit. Of course other libraries will potentially corrupt data on nolock mounts. _______________________________________________ users mailing list users@lists.open-mpi.org https://lists.open-mpi.org/mailman/listinfo/users
