Datapump not working in RAC environment Some minutes ago I've tried to do an export but I get the following error (AIX system):

Additional information: 3
ORA-31693: Table data object "XX"."TABLE_NAME" failed to load/unload and is being skipped due to error:
ORA-31617: unable to open dump file "/dir/back/dump/dump_xx_04.dmp" for write
ORA-19505: failed to identify file "/dir/back/dump/dump_xx_04.dmp"
ORA-27037: unable to obtain file status
IBM AIX RISC System/6000 Error: 2: No such file or directory


What could the reason for this behaviour be? 

I've read in some blog that using just parallel=N without %U that the export is actually slower. Is that true?
I've found the problem.

The doc ID 1597395.1 says:


  The problem occurs when Datapump Export is being performed on a
  multi-node RAC where the dumpfile destination is not shared to all
  nodes for access.  Since multiple nodes will be running the Datapump
  job, ALL nodes must have access to the mount point where the dump file
  will be written.


So I've just used the parameter cluster=n in export to resolve it.