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Subject: Re: [OMPI users] Set GID
From: Pavel Shamis (Pasha) (pasha_at_[hidden])
Date: 2008-03-12 06:33:08

Run opensm with follow parameters:
opensm -c -o

It will make 1 loop and will exit (-o parameter). The -c option says to
opensm to generate option file.
The file will be generated under /var/cache/opensm//opensm.opts
Open the file and find line with "subnet_prefix". Replace the prefix
with new one.
Re-ran opensm: /etc/init.d/opensm start
It will automatically load the option file from cache repository and
will use new prefix

Jeff ,
Do we want to add it to Open-MPI FAQ ?


Jon Mason wrote:
> I am getting the following error when I try to run OMPI over my dual
> port IB adapter:
> --------------------------------------------------------------------------
> WARNING: There are more than one active ports on host 'vic20', but the
> default subnet GID prefix was detected on more than one of these
> ports. If these ports are connected to different physical IB
> networks, this configuration will fail in Open MPI. This version of
> Open MPI requires that every physically separate IB subnet that is
> used between connected MPI processes must have different subnet ID
> values.
> Please see this FAQ entry for more details:
> NOTE: You can turn off this warning by setting the MCA parameter
> btl_openib_warn_default_gid_prefix to 0.
> --------------------------------------------------------------------------
> I understand why it is doing the above based on the description in the
> link above, but I cannot seem to find anywhere that will tell me how to
> change the GID to something else.
> Thanks,
> Jon
> _______________________________________________
> users mailing list
> users_at_[hidden]

Pavel Shamis (Pasha)
Mellanox Technologies