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Subject: [OMPI users] How to set up state-less node /tmp for OpenMPI usage
From: Blosch, Edwin L (edwin.l.blosch_at_[hidden])
Date: 2011-11-01 19:31:48


I'm getting this message below which is observing correctly that /tmp is NFS-mounted. But there is no other directory which has user or group write permissions. So I think I'm kind of stuck, and it sounds like a serious issue.

Before I ask the administrators to change their image, i.e. mount this partition under /work instead of /tmp, I'd like to ask if anyone is using OpenMPI on a state-less cluster, and are there any gotchas with regards to performance of OpenMPI, i.e. like handling of /tmp, that one would need to know?

Thank you,

Ed

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WARNING: Open MPI will create a shared memory backing file in a
directory that appears to be mounted on a network filesystem.
Creating the shared memory backup file on a network file system, such
as NFS or Lustre is not recommended -- it may cause excessive network
traffic to your file servers and/or cause shared memory traffic in
Open MPI to be much slower than expected.

You may want to check your compute nodes, what the typical temporari
directory: node. Possible sources of the location of this temporary
directory include the $TEMPDIR, $TEMP, and $TMP environment variables.

Note, too, that system administrators can set a list of filesystems
where Open MPI is disallowed from creating temporary files by settings
the MCA parameter "orte_no_session_dir".

Local host: e8332
File Name: /tmp/159313.1.e8300/openmpi-sessions-bloscel_at_e8332_0/53301/1/shared_mem_pool.e8332<mailto:/tmp/159313.1.e8300/openmpi-sessions-bloscel_at_e8332_0/53301/1/shared_mem_pool.e8332>
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