Errors in MPI-POSIX VFD at 16K concurrency

Hi,

I have a program that uses MPI-POSIX with chunking to write data to a
shared file from a large number of processors. It succeeds at 8K
concurrency, but when I try at 16K I get the error messages attached.
Any ideas what is causing this "low-level" write failure?

Thanks
Mark

hdf5-errors.txt (66.6 KB)