[Beowulf] Rocks 4.3 and user accounts

Guillaume Michal gmichal at uow.edu.au
Tue Feb 5 04:33:32 PST 2008


Hi all, ( sorry for the duplicate mail, previous one was sent while I
didn't finished it...)

I'm in a process of deploying a HPC based on the rocks distribution.
After some troubles to install the system, I finally succeeded. Nodes
are up and everything seems find when I look at the Ganglia reports.
However I have some troubles with the users accounts. I googled to find
some info  without success so I try here in  case some of you are more
used to Rocks than me. 

Here is the problem, I decided to launch a simple test using mpirun from
mpich as described in the user guide (chapter 2.1 Launching Interactive
jobs). As specified, I created a user and synced the nodes from the
frontend:
# useradd someuser 
# rocks sync users

Then created the "machines" file and put it in the user home directory 
( /export/home/someuser ):
compute-0-0
compute-0-1

And followed the procedure to run it after putting the "HPL.dat" I found
in /var/www/blahblahblah in the user home directory.
	$ ssh-agent $SHELL
	$ ssh-add
	$ /opt/mpich/gnu/bin/mpirun -nolocal -np 2 -machinefile
machines /opt/hpl/mpich-hpl/bin/xhpl

At the moment the problem seems to be the rsa key and ssh. the $HOME
variable is set to /home/someuser whereas the real home is
in /export/home/someuser on the frontend. It leads to some errors when
creating the RSA key as it looks into /home/someuser to create the
files.
I modified the $HOME variable but while it's ok on the frontend, it is
not on the nodes as they expect something in /home/someuser. 
I though the problem was due to the useradd command so I decided to
create the user under Gnome (there must be a way in the console, 'd like
to know it btw...) by specifying the real path to the home user
(/export/home/someuser).
It was then possible to create the key properly. However as soon as I
sync the users on the cluster ( rocks sync users ), the $HOME variable
is set back to /home/someuser -> go back to the beging.

For me it appears to be a problem with the $HOME variable which should
be /export/home/someuser on the frontend and /home/someuser on the
nodes, but this should be automatically defined by Rocks, shouldn't it?

So basically how can I create users account with rsa key, sync the
cluster and still keep the right $HOME variables? I'm kind of lost here
or I clearly miss a point somewhere.

BTW, I kind of tweek "/etc/profile" to modify the $HOME variable and
declare it properly. As I did a standard Rocks installation I do not
believe one has to do this, apart from the fact it's a dirty method :-(

Thank you for your advices

Guillaume  




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