/home/mythtv/.xsession-errors

I have been running knoppmyth for a few years now and the past 8 months or so I didn't think much but my root filesystem was slowly filling up (even after the log fix ) and I finally sat down and found out why.. It would seem over 2 or so years that file had swelled up to be about 50% of the space knoppmyth allocates to the root partition.

I'm not sure log rotate will work with it since unless the X session is stopped it doesn't get closed.

On the other hand a sequence like this run once a week should do the trick:

Just make sure that no one is using the FE when you do it or you may end up in the dog house...