Posted by StyxUT on Feb 17, 2016; 3:38am
URL: https://itus.accessinnov.com/Welcome-all-Itus-Shield-owners-tp5p89.html

It turns out Snort provides a way to limit the size of the IPS log through its configuration file(s).  
Reference section 2.6.3.1 here: http://manual.snort.org/node21.html

If you edit the output line (which happens to be the first line) of /etc/snort/snort7.conf and and snort8.conf you can set a size limit at the end of the line.

E.g. output alert_fast: alert.fast 1M