[mpich-discuss] importance of /tmp/mpd2.console_root?

[Rajeev Thakur]

From: Ralph Butler
Sent: Friday, October 03, 2008 5:43 PM
Subject: Re: [mpich-discuss] importance of /tmp/mpd2.console_root?

A file in /tmp named mpd2.console_XXXX is a Unix socket.  It is used by
mpiexec (and other pgms) to connect to mpd.  Typically XXXX is the name of a
particular user who started the mpd and the socket can only be connected to
by that user.  However, if XXXX is root, and mpd was installed correctly,
then other users may connect to the socket and run jobs.  The socket should
be removed when the mpd exits gracefully, e.g. via mpdallexit.  However, it
may be left when an mpd fails.  But an old file should be removed when a new
mpd starts. 


________________________________

	From: owner-mpich-discuss at mcs.anl.gov
[mailto:owner-mpich-discuss at mcs.anl.gov] On Behalf Of Sangamesh B
	Sent: Friday, October 03, 2008 1:22 AM
	To: MPICH ML
	Subject: [mpich-discuss] importance of /tmp/mpd2.console_root?
	
	
	Hi all,
	
	     I want to know the importance of "mpd2.console_root" file.
	
	     This file gets created after launching the mpd's in /tmp
directory.
	
	srwxrwxrwx 1 root   root      0 Oct  3 11:21 mpd2.console_root
	
	     When mpd's are stopped, this file get deleted automatically.
	
	I'm curious to know about this because, recently I faced a problem
with mpdboot. mpdboot was not happening and gave error with a particular
node. I googled the error, then I came to know that its problem with the
above file.
	 
	Eventhough, there was no mpd(as user root) running on that node, the
file /tmp/mpd2.console_root was present. I tried to delete. But it couldn't
delete.
	
	So why this file is required? In the above case what's the wayout?
	
	Thanks,
	Sangamesh