mdsh.com/wiki

On Ubuntu (at least with 8.04 LTS) Tomcat is very nicely setup with CATALINA_HOME=/usr/share/tomcat5.5 and CATALINA_BASE=/var/lib/tomcat5.5
That's great, but I like my config files, which would live in the conf directory of $CATALINA_BASE to live on the same NFS mount as the web sites, which gets mounted onto /usr/local/sites, so...

sudo /etc/init.d/tomcat5.5 stop
cd /var/lib/tomcat5.5/
sudo rm conf
sudo ln -sf /usr/local/sites/etc/tomcat/conf/ conf
sudo /etc/init.d/tomcat5.5 start
/var/lib/tomcat5.5/conf was only a sym-link to /etc/tomcat5.5 so we haven't lost anything - it's easy to put back if needed.