[MPICH] Running on root's MPD as either root or another user

[Matthew Chambers]

Ah, the s bit has to be on the owner's set, I hadn't tried that (and 
don't really understand why). But now I'm back to mpiexec locking up 
when I try to run a job from the user's account, and when I break the 
process, I get:
(mpiexec 413): mpiexec: failed to obtain sock from manager
And also there's a stranded mpd process in the process list each time I 
try:
rslebos 27003 10967 0 16:58 ? 00:00:00 python2.4 
/frogstar/usr/ppc/bin/mpd --listenport=4050 --ifhn=172.20.0.1 --dae
rslebos 27008 10967 0 16:58 ? 00:00:00 python2.4 
/frogstar/usr/ppc/bin/mpd --listenport=4050 --ifhn=172.20.0.1 --dae
rslebos 27028 10967 0 17:00 ? 00:00:00 python2.4 
/frogstar/usr/ppc/bin/mpd --listenport=4050 --ifhn=172.20.0.1 --dae

Confused...
-Matt

Ralph Butler wrote:
> The key is to make sure the mpd files are installed as setuid-root as 
> described in the manual.
> Here's the relevant blurb:
>
> 5.1.6 Running MPD as Root
> MPD can run as root to support multiple users simultaneously. To do this,
> it easiest to simply do the “make install” in the mpd sub-directory as 
> root.
> This will cause the mpdroot program to be installed in the bin 
> directory with
> setuid-root permissions.
>
> If things are already installed, you can alter mpdroot's permissions 
> with the chmod
> command, e.g.:
> chmod +s mpdroot
>
> --ralph
>
> On MonOct 1, at Mon Oct 1 3:03PM, Matthew Chambers wrote:
>
>> Hi all,
>>
>> The install guide seems unclear about how to do this or if it's even 
>> possible. I have my user's .mpd.conf as:
>> MPD_SECRETWORD=foo
>> MPD_USE_ROOT_MPD=1
>>
>> And my /etc/mpd.conf is:
>> MPD_SECRETWORD=foo
>>
>> Permissions on the user's conf are: -rwx------
>>
>> When permissions on the /etc/mpd.conf are: -rwx------
>> I can run mpdtrace and MPI jobs as root just fine, but when I try 
>> either of those as the user, I get "open failed for root's mpd conf 
>> filempdtrace: mpd_uncaught_except_tb handling"
>>
>> So when I set permissions on the /etc/mpd.conf are: -rwx---r--
>> I can run mpdtrace as the user, but when I try to run an MPI job 
>> (e.g. mpiexec -n 16 hostname ; not an MPI program, but still works 
>> fine with MPICH2), it hangs. When I break it with CTRL-C I get the 
>> message "(mpiexec 413): mpiexec: failed to obtain sock from manager". 
>> I can't run mpdtrace or MPI jobs as root because of: "configuration 
>> file /etc/mpd.conf is accessible by others \ change permissions to 
>> allow read and write access only by you". This seems a bit of a 
>> catch-22.
>>
>> I'm mostly interested in getting it working for the user. I don't 
>> have the MPD binaries installed in the standard location, so I'm not 
>> sure how to set the permissions. I tried setting everything to: 
>> -rwxr-sr-x
>> But that has the same error. The user only has an account on the head 
>> node, is that the problem?
>>
>> Thanks,
>> Matt Chambers
>>
>
>