Keep /var/log logs longer

I recently tried to increase the amount of log data which is kept in /var/log on my Ubuntu box. The log files are usually rotated using logrotate, or so I thought. The first thing I did was editing

/etc/logrotate.conf

I set the interval to monthly and rotate 24, but this did not help.

I seems like half of the log files are rotated by savelog which is triggered daily by cron. So I moved the file

/etc/cron.daily/sysklogd

to cron.monthly and edited the number of cycles to 120 (10 years, -c 120. This seems to do the trick. :-)