[mythtv-users] Slave backend time sync problem after DST change

DaveD mythtv at guiplot.com
Mon Mar 31 04:25:02 UTC 2014

Just wanted to share this info with anyone who comes looking in the future:

I've had a remote FE/slave BE system online for a while, now, and all 
was working well until daylight ^%*!ing saving time went into effect and 
mythbackend started failing on system boot.  After missing a couple of 
recordings, I began checking to be sure the backend was running after 
every boot, and always found it wasn't, then started the service by 
hand, until I finally got around to checking the backend log and found 
the following:

Current time on the master backend differs by 3600 seconds from time on 
this system. Exiting

The 3600 tells it all.  I'm pretty sure the system worked last summer 
and no problems then or when we went off DST, but this transition 
buggered things up.

I used to run the NTP daemon to keep things in sync, but after the last 
upgrade (to Fedora 17), it didn't seem to need it.  I don't know for 
certain, but I'm guessing the GUI (kde) is doing the time sync.  When I 
set it up I used the GUI to turn on the "sync with time server" under 
time/date stuff and forgot about it.  If the GUI (kde) is taking care of 
the time sync, it would explain why the backend craps on startup, before 
the GUI time sync routine is loaded and compensating for the DST.

With that in mind, I solved the problem with the following command 
issued from a console as root:

systemctl enable ntpdate.service

That's it!  Now the ntpdate "service" is enabled, which syncs the system 
with a network time server first thing when it boots, before mythbackend 
starts.  I haven't checked to see if it is, but ntpdate could be a 
prerequisite of the mythbackend service (will check for that if it ever 
fails due to a race that has yet to be lost).

No more backed exits after reboot.  No more missed shows!  Wife is 
happy!  Life is good!

Dave D.

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