I have a few servers running Tiger that were installed before I took over the IT Department where I work. These servers also run LXC and use the cgroup “filesystem” type and thus Tiger has a problem whenever it runs it's checks throwing the following error and thus making Cron send a mail about the situation:
--CONFIG-- [con010c] Filesystem 'cgroup' used by 'cgroup' is not recognised as a valid filesystem
To get rid of these messages you have2 options (an entry in /etc/tiger/tiger.ignore has no effect).
1. wait until cgroup is added as a valid Fstype in Tiger. 2. Modify the script responsible for this so you don't have to wait for an update.
Seeing as how it takes a while for anything to get updated in Tiger the best option, from my point of view, is just to go ahead and modify Tiger yourself.
To do so is simple. Just open (on Debian) /usr/lib/tiger/systems/Linux/2/gen_mounts in your favorite editor and search for “localfs()”. Slightly below that entry you will see a line along the lines of “LOCAL=2” and then a comment like “#Valid local filesystems”.
Find a nice spot somewhere in the list and make the following entry:
[ "$1" = "cgroup" ] && LOCAL=0 # Control Group FS
Save it and walk away.