On 02/25/2015 02:01 AM, vithanousek wrote:
Do you know how to use OMPIO without mounting pvfs2? if I tryed the same filename format
as in ROMIO I got "MPI_ERR_FILE: invalid file".
If I use normal filename format ("/mountpoint/filename") and force use of pvfs2
by using --mca io ompio --mca fs pvfs2, then my app fails with
mca_fs_base_file_select() failed (and backtrace).
Sorry, I forgot to mention the importance (to ROMIO) of the file system
prefix. ROMIO can detect file systems two ways:
- either by using stat
- or by consulting a "file system prefix"
For PVFS2 or OrangeFS, prefixing the file name with 'pvfs2:' will tell
ROMIO "treat this file like a PVFS2 file", and ROMIO will use the
"system interface" to PVFS2/OrangeFS.
This file system prefix is described in the MPI standard and has proven
useful in many situations.
Edgar has drawn the build error of OMPI-master to my attention. I'll
get that fixed straightaway.
==rob
At OrangeFS documentation (http://docs.orangefs.com/v_2_8_8/index.htm) is
chapter about using ROMIO, and it says, that i shoud compile apps with -lpvfs2.
I have tryed it, but nothing change (ROMIO works with special filename format,
OMPIO doesnt work)
Thanks for your help. If you point me to some usefull documentation, I will be
happy.
Hanousek Vít
---------- Původní zpráva ----------
Od: Rob Latham
Komu: us...@open-mpi.org, vithanou...@seznam.cz
Datum: 24. 2. 2015 22:10:08
Předmět: Re: [OMPI users] MPIIO and OrangeFS
On 02/24/2015 02:00 PM, vithanousek wrote:
Hello,
Im not sure if I have my OrangeFS (2.8.8) and OpenMPI (1.8.4) set up corectly.
One short questin?
Is it needed to have OrangeFS mounted through kernel module, if I want use
MPIIO?
nope!
My simple MPIIO hello world program doesnt work, If i havent mounted OrangeFS.
When I mount OrangeFS, it works. So I'm not sure if OMPIO (or ROMIO) is using
pvfs2 servers directly or if it is using kernel module.
Sorry for stupid question, but I didnt find any documentation about it.
http://www.pvfs.org/cvs/pvfs-2-8-branch-docs/doc/pvfs2-quickstart/pvfs2-quickstart.php#sec:romio
It sounds like you have not configured your MPI implementation with
PVFS2 support (OrangeFS is a re-branding of PVFS2, but as far as MPI-IO
is concerned, they are the same).
OpenMPI passes flags to romio like this at configure time:
--with-io-romio-flags="--with-file-system=pvfs2+ufs+nfs"
I'm not sure how OMPIO takes flags.
If pvfs2-ping and pvfs2-cp and pvfs2-ls work, then you can bypass the
kernel.
also, please check return codes:
http://stackoverflow.com/questions/22859269/what-do-mpi-io-error-codes-mean/26373193#26373193
==rob
Thanks for replays
Hanousek Vít
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Rob Latham
Mathematics and Computer Science Division
Argonne National Lab, IL USA
