I’ve installed HA on a Raspbian Raspberry Pi 4 (with a Conbee II) and it’s been running OK, but it looks like I need the additional capabilities of HA add-ons and Supervisor.
Is there a way to upgrade my current installation to HA OS without overwriting or otherwise disrupting the rest of my Raspbian installation ?
Well, that’s kind of what I’m wondering: Is HA OS actually a complete replacement for Raspbian (or any other host OS), rather than (say) an installable platform layer ? So if I install HA SO, it is unavoidable that I will completely lose my existing Raspbian system ?
After some reading, it looks like I want to upgrade to Home Assistant Supervised. That should give me add-ons and Supervisor without having to overwrite my current Debian installation.
AFAICT Home Assistant Supervised is not as well-documented as the other three installation methods, but at least it seems to be supported on Debian (altho not on other flavors of Linux).
You don’t have a Debian installation, you have Raspberry Pi OS (formerly Raspbian) which is a derivative of Debian. Home Assistant Supervised is officially supported exclusively on Debian and not on any other distro of Linux, not even derivatives of Debian. This is all clearly explained in the installation instructions for Home Assistant Supervised.
You are, of course, free to install it on Raspberry Pi OS but the result will be an unsupported system (it will indicate this in Settings > System > Repairs). What does “unsupported” mean? It means you cannot receive support from the development team (i.e. in GitHub) for any problems that may arise with your system. Your source of assistance is limited to community forum(s).
In addition, the requirements for Home Assistant Supervised evolve over time. The requirements and associated installation script only take Debian into account and no other Linux distro. In fact, recent versions of the installation script refuse to work with non-Debian systems so you’re obliged to perform its tasks manually. This makes adapting your unsupported system, to meet the latest requirements, just that much more challenging.
Now that you know the consequences, you can make an informed decision about how you wish to proceed.