Tvheadend

My Tvheadend setup is constantly crashing and restarting for a few hours (see attached log).
I suspect it to be due to the fact that my disk is full (see other message Automatic cleaning of recordings).
The EPG must be corrupted. Deleting ~/.hts/tvheadend/epgdb allows tvheadend to restart.
This behaviour occurs to me regularly, when my hard disk is full. Manually deleting some old recordings solves it, and then these problems occur again when my disk is full.

Also, the newly executed instances of tvheadend each run an XMLTV subprocess (tv_grab_fr). I sometimes get dozens of these processes. Shouldn't it check if another instance of the grabber is already present before executing it?
I have noticed that when it works, my grabber (tv_grab_fr) needs a few hours to complete.

Thanks!