After setting up several virtual machines I quickly realized how easy it can be to lose track of things. To help set things straight, I installed cacti which allows me a quick glance over all my machines and devices. However, I soon outgrew just using graphs and needed a way to receive email notifications when things broke. I didn’t want to invest more time to a different solution and debians package for cacti is older and makes it very difficult to add the plugin architecture.
The solution is simple and assumes an upgrade from 0.8.7g (apt-get install cacti). In summary, overwrite the files, visit the cacti page, click upgrade and done.
tar xvzf cacti-0.8.8a.tar.gz
mv /usr/share/cacti/site /usr/share/cacti/oldsite
mv cacti-0.8.8a /usr/share/cacti/site
rm -r /usr/share/cacti/site/rra
ln -s /var/lib/cacti/rra /usr/share/cacti/site/rra
mv /usr/share/cacti/oldsite/include/config.php /usr/share/cacti/site/include/
Visit your cacti page and push upgrade and next a couple of times and you should be fully upgraded with everything still working fine. At this point you can put any plugins into the /usr/share/cacti/site/plugins directory and install via the web management.
Edit (1/27): In retrospect, I should have removed the debian package and installed 0.8.8a cleanly. Suppose I was tired and wanted a quick fix last night.