I constantly get this nonsense in my logwatch mail:
**Unmatched Entries** crond: pam_systemd(crond:session): Failed to create session: File exists: 1 Time(s)
That apparently corresponds to this entry in /var/log/secure:
Jun 16 08:42:01 tomh crond[25783]: pam_systemd(crond:session): Failed to create session: File exists
And that was apparently generated by this cron job:
Jun 16 08:42:01 tomh CROND[25788]: (tweety) CMD (/usr/bin/fetchmail -s >> $HOME/.fetchmail.log 2>&1)
What in the blue blazes is it talking about? What file already exists? The fetchmail job runs every minute. Does this happen when the previous fetchmail cron job hasn't finished yet? It would sure be helpful if someone mentioned what file it is that already exists :-).