The following are potential configuration items that you may want to fix:
1: some network boot-loaders are missing from /var/lib/cobbler/loaders. If you only want to handle x86/x86_64 netbooting, you may ensure that you have installed a *recent* version of the syslinux package installed and can ignore this message entirely. Files in this directory, should you want to support all architectures, should include pxelinux.0, menu.c32, and yaboot.
2: debmirror package is not installed, it will be required to manage debian deployments and repositories
3: fencing tools were not found, and are required to use the (optional) power management features. install cman or fence-agents to use them
Restart cobblerd and then run 'cobbler sync' to apply changes.