A little something to save frustration when working with rsync and public/private keys. Be sure to pass the key you'd like to use (if not using default values):
ssh -i /root/.ssh/key_file_you_want_to_use
And if you're using cPanel, you might consider using
to limit CPU usage when running something that might take a while (like rsync-ing your backups to external locations). The 1.5 parameter above checks to make sure the server load is below that value before continuing.
This mainly helps me since I will inevitably forget this and need to know where to look. Leaving these breadcrumbs around makes a certain kind of sense.