[mythtv-users] Mythbackend crashes randomly

Mark Adams mark9117 at gmail.com
Sat Aug 9 17:37:50 UTC 2008

I have an installation of MythTV 0.21 under Mandriva 2008.1.

I can provide requested information, but the in a nutshell the problem 
is that the backend is randomly crashing. 

 From time to time, I'll check the system to find that Mythbackend is 
not running.  I don't find anything recent in 

To try and cope with this, I wrote a shell script:
if ps ax | grep -v grep | grep mythbackend > /dev/null
    echo "Mythbackend service running, everything is fine"
    echo "Mythbackend is not running"
   echo "Mythbackend is not running!" | mail -s "Mythbackend down" 
root at shuttle
        service mythbackend start
This is supposed to notify root that mythbackend isn't running and try 
to start the process.  It runs as a cron job 20, 40 and 57 minutes after 
the hour.  This morning I got a notification at 3:20 and was notified at 
every running thereafter until I caught it at 10:40.  So, running this 
script from cron isn't able to start the process.  Running the script 
manually, or even starting the cron job from Webmin starts Mythbackend 
just fine.  On startup, I'm seeing this.  It looks good:

2008-08-09 11:26:00.951 Connected to database 'mythconverg' at host: 
[root at pvr mythtv]# 2008-08-09 11:26:00.952 Closing DB connection named 
2008-08-09 11:26:00.953 Connected to database 'mythconverg' at host: 
2008-08-09 11:26:00.954 New DB connection, total: 2
2008-08-09 11:26:00.955 Connected to database 'mythconverg' at host: 
2008-08-09 11:26:00.957 Current Schema Version: 1214
Starting up as the master server.
2008-08-09 11:26:00.967 New DB connection, total: 3
2008-08-09 11:26:00.968 Connected to database 'mythconverg' at host: 
2008-08-09 11:26:01.018 New DB scheduler connection
2008-08-09 11:26:01.018 Connected to database 'mythconverg' at host: 
2008-08-09 11:26:02.256 Main::Registering HttpStatus Extension
2008-08-09 11:26:02.257 mythbackend version: 0.21.20080304-1 www.mythtv.org
2008-08-09 11:26:02.257 Enabled verbose msgs:  important general
2008-08-09 11:26:02.275 AutoExpire: CalcParams(): Max required Free 
Space: 1.0 GB w/freq: 15 min
2008-08-09 11:26:04.028 Reschedule requested for id -1.
2008-08-09 11:26:04.797 Scheduled 41 items in 0.8 = 0.06 match + 0.70 place
2008-08-09 11:26:04.819 Seem to be woken up by USER
2008-08-09 11:26:11.045 New DB connection, total: 4
2008-08-09 11:26:11.050 Connected to database 'mythconverg' at host: 
2008-08-09 11:26:11.084 UPnpMedia: BuildMediaMap VIDEO scan starting in 
2008-08-09 11:26:11.089 UPnpMedia: BuildMediaMap Done. Found 0 objects

As near as I can tell the only issue showing up in logs is I'm finding 
segfaults in dmesg.  I'm not sure exactly when they appear or why, but 
surely they are related to the crash of Mythbackend:

mythbackend[24571]: segfault at 00000010 eip 08071aa2 esp b04aaea0 error 4

mythbackend[31998]: segfault at 00000028 eip 08071aa2 esp b12fe180 error 4

Anybody have any ideas?


Mark E. Adams

Random Musing: 
Love at first sight is one of the greatest labor-saving devices the
world has ever seen.

More information about the mythtv-users mailing list