Hi,
No, there should be no limitations to using a socket-based MPICH build
on a VM.
Ken
On 05/01/2017 10:56 AM, Dmitriy Lyubimov wrote:
> Hi,
> are there known issues when running mpich (3.3a) on VMs? I am seeing
> spurious failures of different kind on VMs that i never had seen in
> barebone environment. This is (I think) with the sockets channel. Is it
> worth pursuing in terms of trying to get to the bottom of it, or it is a
> known limitation?
>
> Thanks!
> -Dmitriy
>
>
> _______________________________________________
> discuss mailing list discuss(a)mpich.org
> To manage subscription options or unsubscribe:
> https://lists.mpich.org/mailman/listinfo/discuss
>
_______________________________________________
discuss mailing list discuss(a)mpich.org
To manage subscription options or unsubscribe:
https://lists.mpich.org/mailman/listinfo/discuss
Hello,
I am experiencing issues on the SDSC Comet system when using the intel
compilers with mvapich2. The scheduling system on Comet is slurm. It seems
like the code is seg-faulting inside of MPI_Comm_dup, but prior to that, it
seems like it is rejecting a connection request to "self" (i.e., same IP to
same IP).
The modules loaded are:
```
$ module list
Currently Loaded Modulefiles:
1) intel/2013_sp1.2.144 2) mvapich2_ib/2.1 3) gnutools/2.69
```
I am attempting to use the `ib0` interface. In my job script, I am
launching 3 different applications. I am **not** using slurm
`--multi-prog`. I am instead using 3 different `srun` commands. My job has
to be launched this way.
Using OpenMPI, I can set the MCA parameters to allow connections from
`self` at the byte-transfer layer, i.e., `OMPI_MCA_btl="self,openib"` and
specify to slurm that I would like to use `--mpi=pmi2`.
I think the mvapich errors that I am experiencing stem from the fact that
the "self" connection is rejected (i.e., node to itself). Is there a way to
tell MVAPICH to allow the self connection? I think I want the
`--with-device=ch3:nemesis:ib`
command in some capacity, but I'm not sure if that would be enough to allow
the connection from the node to itself. Is the self connection inherently a
TCP connection? Or do I still need `--mpi=pmi2` for srun? Can I use srun or
do I need to use `mpiexec` explicitly?
Could this also be the cause of the error described by this FAQ?
https://wiki.mpich.org/mpich/index.php/Frequently_Asked_Questions#Q:_All_my…
.
Any help you can provide is greatly appreciated.
-Melissa
_______________________________________________
discuss mailing list discuss(a)mpich.org
To manage subscription options or unsubscribe:
https://lists.mpich.org/mailman/listinfo/discuss
Hi,
are there known issues when running mpich (3.3a) on VMs? I am seeing
spurious failures of different kind on VMs that i never had seen in
barebone environment. This is (I think) with the sockets channel. Is it
worth pursuing in terms of trying to get to the bottom of it, or it is a
known limitation?
Thanks!
-Dmitriy
_______________________________________________
discuss mailing list discuss(a)mpich.org
To manage subscription options or unsubscribe:
https://lists.mpich.org/mailman/listinfo/discuss
I am trying to assess how well a high-performance file system that I work
on will support MPI programming for some customers we have. In particular,
I am looking at MPI I/O.
The technical aspects of the assessment are pretty simple. Collective and
direct I/O should work great, but the locking apparently required for
atomic mode I/O will be very, very expensive.
That leads to the community questions of how important these trade-offs
will be. And thus, I land here on this list.
I have a few questions that folk here probably can answer off the top of
their head:
1) how often is atomic mode I/O used? It seems that most I/O will involve
non-overlapping writes and thus atomic mode will be irrelevant. But what is
the real sense from people who actually write this kind of code?
2) do commonly used MPI libraries implement atomic mode internally as in
[1], or do they require file system support? What kind of support?
3) how to file-system people usually go wrong in approaching MPI
applications?
[1] http://www.mcs.anl.gov/~thakur/papers/atomic-mode.pdf
_______________________________________________
discuss mailing list discuss(a)mpich.org
To manage subscription options or unsubscribe:
https://lists.mpich.org/mailman/listinfo/discuss
