I was having trouble with any of the logs managed by rsyslog not rotating. This resulted in a number of huge log files, especially the /var/log/syslog file. Not only those but also others from remote systems since I was using this server as a syslog server.

All I needed to do is comment out the following line in the /etc/rsyslog.conf file:

$PrivDropToUser syslog

I restarted the rsyslog service.

# service rsyslog restart