I've got it installed, and backing itself up, but the first client system is throwing errors on me. Firewall ports are open and services running according to the guide here. It'll be this afternoon before I can get around to looking at the error logs.

Got it.

So after you have postgres installed, you can just install the package for your distro.

From that, you run a few commands (of course these are strewn all about) and then reload the config (or reboot the host) and you can sign in.