Opscenter UI will show the node hostname as "unknown"
The user will be showing all agents connected in the UI and all stats will be showing up for the node like load, disc space etc but the hostname will show up as "unknown"
The node had incorrect permissions on /etc/hosts.
$ ls -l /etc/hosts -rw-r-----. 1 root root 177 Aug 19 2014 /etc/hosts
Ensure /etc/hosts has at least 644 permissions
$ ls -l /etc/hosts -rw-r--r--. 1 root root 177 Aug 19 2014 /etc/hosts