[mpich-discuss] open failed for root's mpd conf

Wed Mar 17 17:10:05 CDT 2010

OK, I suppose that theory didn't pan out.

You could try something like the following to see why the open for "/ 
etc/mpd.conf" is failing, but you will need a setuid root version of  
strace:

-----8<-----
strace -f -e trace=file 2>&1 | grep mpd.conf
-----8<-----

I don't remember exactly how to get a proper setuid strace  
installation, although it may be as simple as "sudo chmod u+s /path/to/ 
strace ; sudo chown root /path/to/strace".  Please be aware that  
allowing arbitrary users to execute setuid root strace is a *huge*  
local security hole.  So if this is a multi-user system then you  
should restrict execution to users in a trusted group and only mess  
around with this on a copy of the file.  See the strace man page if  
you want to go down this path.

Or just run the mpd ring as your user.  I wouldn't personally  
recommend running something as fragile as mpd as root anyway, even  
though it is technically possible.

Alternatively, ditch mpd altogether and try the hydra process manager: http://wiki.mcs.anl.gov/mpich2/index.php/Using_the_Hydra_Process_Manager

It doesn't require setting up any daemons in the common case.

-Dave

On Mar 17, 2010, at 4:51 PM, rcx11 at yahoo.com wrote:

> Output of "strings /usr/bin/mpdroot | grep etc" yielded "/etc/ 
> mpd.conf" Setting the environment variable failed. I made a symlink  
> to /etc/mpd.conf in /usr/etc/mpd.conf. This also failed.
>
> --- On Wed, 3/17/10, Dave Goodell <goodell at mcs.anl.gov> wrote:
>
>> From: Dave Goodell <goodell at mcs.anl.gov>
>> Subject: Re: [mpich-discuss] open failed for root's mpd conf
>> To: mpich-discuss at mcs.anl.gov
>> Date: Wednesday, March 17, 2010, 4:33 PM
>> Well, if my earlier suggestion about
>> "/etc/mpd.conf" doesn't solve the problem, then I am not
>> entirely sure what is going on.
>>
>> I just took a peek at the code and it looks like we may
>> have a bug in the root mpd.conf search path that was
>> introduced in r5844.  We now search
>> "@sysconfdir@/mpd.conf" (which expands to
>> "${prefix}/etc/mpd.conf" normally) instead of
>> "/etc/mpd.conf".  So I'm betting that you have a valid
>> "/etc/mpd.conf" but mpdroot is looking for it in
>> "/usr/etc/mpd.conf" instead.
>>
>> Can you try two things for me?  First run the
>> following command and send us the output: "strings
>> /usr/bin/mpdroot | grep etc".  Second, try setting the
>> environment variable "MPD_CONF_FILE=/etc/mpd.conf" before
>> running mpiexec.  That may let you work around the
>> problem for now.  Alternatively you could probably move
>> your "/etc/mpd.conf" to the "/usr/etc/" directory.
>>
>> -Dave
>>
>> On Mar 17, 2010, at 3:59 PM, rcx11 at yahoo.com
>> wrote:
>>
>>> That is exactly what I'm trying to do - run on a root
>> started ring as a normal user. I get no errors when running
>> as root.
>>>
>>> --- On Wed, 3/17/10, Dave Goodell <goodell at mcs.anl.gov>
>> wrote:
>>>
>>>> From: Dave Goodell <goodell at mcs.anl.gov>
>>>> Subject: Re: [mpich-discuss] open failed for
>> root's mpd conf
>>>> To: mpich-discuss at mcs.anl.gov
>>>> Date: Wednesday, March 17, 2010, 3:46 PM
>>>> Just to be sure, you are trying to to
>>>> use a root-started mpd ring as a
>>>> regular user, correct?  If so, make sure that
>> you have
>>>> a mode 600 file
>>>> named "/etc/mpd.conf" (no leading ".") containing
>> the
>>>> secret word.
>>>>
>>>> If you are trying to use a regular user-started
>> mpd ring as
>>>> a regular
>>>> user, then remove "MPD_USE_ROOT_MPD=yes" from
>> your
>>>> "~/.mpd.conf".
>>>>
>>>> -Dave
>>>>
>>>> On Mar 17, 2010, at 3:33 PM, rcx11 at yahoo.com
>>>> wrote:
>>>>
>>>>> It's "MPD_USE_ROOT_MPD=yes" as per setup guide
>> in the
>>>> link given.
>>>>>
>>>>> --- On Wed, 3/17/10, Dave Goodell <goodell at mcs.anl.gov>
>>>> wrote:
>>>>>
>>>>>> From: Dave Goodell <goodell at mcs.anl.gov>
>>>>>> Subject: Re: [mpich-discuss] open failed
>> for
>>>> root's mpd conf
>>>>>> To: mpich-discuss at mcs.anl.gov
>>>>>> Date: Wednesday, March 17, 2010, 3:02 PM
>>>>>> On Mar 17, 2010, at 2:50 PM, rcx11 at yahoo.com
>>>>>> wrote:
>>>>>>
>>>>>>> I've been searching through
>> documentation
>>>> trying to
>>>>>> find why I'm getting the error when trying
>> to run
>>>> as a
>>>>>> non-root user. I'm running Fedora 12 x86
>> and have
>>>> installed
>>>>>> MPICH2 via yum. I've got my mpd.conf files
>> created
>>>> according
>>>>>> to http://debianclusters.cs.uni.edu/index.php/MPICH_without_Torque_Functionality
>>>>
>>>>>> .
>>>>>> When trying to run mpiexec as a non-root
>> user, I
>>>> get the
>>>>>> error "/usr/bin/mpdroot: open failed for
>> root's
>>>> mpd conf
>>>>>> filempiexec_sebastian.ags-rolla.zapto.org
>>>> (__init__ 1208):
>>>>>> forked process failed; status=255" What is
>> causing
>>>> this?
>>>>>>
>>>>>> Please see section 5.1.6 of the
>> Installer's Guide:
>>>> http://www.mcs.anl.gov/research/projects/mpich2/documentation/files/mpich2-1.2.1-installguide.pdf
>>>>>>
>>>>>> Do you have "MPD_USE_ROOT_MPD=1" set
>> somewhere in
>>>> your
>>>>>> environment or mpd.conf file?
>>>>>>
>>>>>> -Dave
>>>>>>
>>>>>>
>> _______________________________________________
>>>>>> mpich-discuss mailing list
>>>>>> mpich-discuss at mcs.anl.gov
>>>>>> https://lists.mcs.anl.gov/mailman/listinfo/mpich-discuss
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>> _______________________________________________
>>>>> mpich-discuss mailing list
>>>>> mpich-discuss at mcs.anl.gov
>>>>> https://lists.mcs.anl.gov/mailman/listinfo/mpich-discuss
>>>>
>>>> _______________________________________________
>>>> mpich-discuss mailing list
>>>> mpich-discuss at mcs.anl.gov
>>>> https://lists.mcs.anl.gov/mailman/listinfo/mpich-discuss
>>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> mpich-discuss mailing list
>>> mpich-discuss at mcs.anl.gov
>>> https://lists.mcs.anl.gov/mailman/listinfo/mpich-discuss
>>
>> _______________________________________________
>> mpich-discuss mailing list
>> mpich-discuss at mcs.anl.gov
>> https://lists.mcs.anl.gov/mailman/listinfo/mpich-discuss
>>
>
>
>
> _______________________________________________
> mpich-discuss mailing list
> mpich-discuss at mcs.anl.gov
> https://lists.mcs.anl.gov/mailman/listinfo/mpich-discuss