First time I tried that was the case, I then started smpd in root instead of in user. This made the uid=0 as you said it should. So I can confirm that I can run mpiexec id as root and get the expected answers. Yes I am still running smpd but if someone can verify that the program I provided works with hydra I will configure MPICH with hydra and never look at smpd again. Eibhlin ________________________________________ From: Pavan Balaji [[email protected]] Sent: 16 June 2013 14:23 To: Lee, Eibhlin Cc: [email protected] Subject: Re: [mpich-discuss] Running an mpi program that needs to access /dev/mem On 06/16/2013 08:19 AM, Lee, Eibhlin wrote:

Actually, I can run mpiexec id AS ROOT. It is only when I try to run the program that contains /dev/mem in root that there is an issue. Sorry that I wasn't so clear in my earlier post.

Are you sure? Here's what you wrote in a previous email, which indicates that your processes are not running as root: ================================================== sorry when I do run mpiexec id the output is uid=1000(pi) gid=1000(pi) groups=1000(pi),4(adm),20(dialout),24(cdrom),27(sudo),29(audio),44(video),46(plugdev),60(games),100(users),105(netdev),999(input) regardless of whether I'm in root or my usual user. root@raspi or pi@raspi. Is this output what you would expect? ================================================== You further added that you are running this with smpd. -- Pavan -- Pavan Balaji http://www.mcs.anl.gov/~balaji