[MPICH] Multi-homed and default configuration

[Steve Kargl]

On Wed, May 24, 2006 at 05:41:02PM -0500, Ralph Butler wrote:
> Hi Steve:
> 
> On May 24, 2006, at 4:21 PM, Steve Kargl wrote:
> 
> >I've set up mpich2 on a small cluster.  The master node,
> >where users will connect via the internet, is multi-homed
> >with a FQDN and a 192.168 subnet.  I want mpich2 to run
> >on the 192.168 subnet.  In reading the docs, this can be
> >accomplished by
> >
> >mpdboot --ifhn=192.168.0.10 -n 3 -f mpd.hosts
> >
> >where 192.168.0.10 is in the master node and mpd.hosts
> >contains 192.168.0.{11,12,13,14,15}.
> >
> 
> 
> The --ifhn option to mpdboot ONLY affects the local machine where
> the first mpd is always started.  Then, you can specify other ifhn
> values for other hosts in the mpd.hosts file, e.g.:
>     node2 ifhn=192.168.1.2
> 
> >I've scanned the installation and user's guides and the
> >mpich-discuss archive, but can't find the answers to
> >the following questions.
> >
> >Is it possible to have a /etc/mpdboot.conf file and
> >/etc/mpd.hosts file so that a ring of mpd servers can
> >be started by root such that the few users on the
> >system will use this ring?
> >
> 
> No, there is no mpdboot.config file.  But, you can start mpds as
> root and have users use them to run their own jobs.  The users
> have to set the variable named MPD_USE_ROOT_MPD to 1 either in their
> env or in their ~/mdp.conf files.  I believe the name of this var
> is MIS-spelled in the manual with the current release.

Thanks for the reply.  I actually forgot to ask the
question.  To keep a user from having to enter
"--ifhn=192.168.0.10 -f mpd.hosts" each time a user
(or root) fires up mpich2 with mpdboot, it would
seem be a desirable feature to set either global values
in mpdboot.conf or maybe environmental variables.  I
guess I'll have to use csh's alias feature to do

alias mpdboot '/usr/local/bin/mpdboot --ifhn=... -f ...'

> >It appears that --ncpus= option will assume that all
> >nodes have the same numbers of cpus, which may not be
> >the case.  Is it possible to set the number of cpus in
> >a node via the mpd.hosts file?
> >
> 
> Like ifhn, --ncpus is for the local mpd only.  You can specify it in
> the mpd.hosts file this way:
>     node1:4
> which says that there are 4 cpus on node1.  Yes, I know it should
> have been handled the same way as ifhn (i.e. with a ncpus keyword),
> but it was left this way for historical reasons.  :-)

Thanks again.  I must have missed this in the user's guide.
I must admit I read it hastily.

-- 
Steve