I have searched and read a lot of links both here and elsewhere describing how to handle multiple homes. Most go into detail about setting up two HA instances, one at each house (some ‘brought together’ via an addin, others via the remote app supporting multiple instances). A few talk about using one instance between two homes that are already connected via a vlan.
Each of these talks about the technical details of how to implement the solution. But…
I’m pretty technical, comfortable with electrical engineering as well as computer science - I do understand those explanations. But what I cant find, is a clear discussion of why one should or shouldn’t choose one or the other.
I installed haos as a vm at home A, and did nothing other than have it discover local (to home A) devices and make sure all integrations were present. I believe my next step would be to create areas/zones/floors and assign all found devices to them and be done for home A. For home B there is a very stable and high speed vpn between that house and home A. I could simply add a multicast relay to allow the haos at home A to see and thus discover the devices at home b. Easy, but…
I’d prefer to not install a separate haos instance at each house, but that is certainly possible. What I dont want, is for example when using a voice assistant, to have to tell it with every command which house I’m at (Alexa, turn on the FARM master bedroom lights).
Biggest fear is that I will chose a path without input from folks that know better than I, and have no easy way to fix it all other than delete and start over.
Given my specifics, are there any pros and cons from a usability standpoint between the two approaches? Thanks in advance for any and all insight!
I would suggest you could have three sets of commands, one for each home and then one that does not specify the home. Then, you can always use the commands that do not specify the hopme to mean the home of the device that hears the commnand, no? Then you could always also specify the other home in your command to tell it to act appropriately - in either home.
As far as two instances vs. one, I do not think it natively supports multiple homes in one instance - but I am no authority in that realm -
I have same situation with home and gate (except no VPN), I use Naba Casa at both, two different providers for Internet and Remote Home Assistant to link them. it something is close in name, I name using area/use preface like "gate_spotlights).
I do not feel that is a biggie, as I have all things named by location and light type …
gate spotlight front spotlight driveway spotlight backyard spotlight
I have two homes and run independent home assistants located at each home. I’ve been doing that for 3 years. I do have the LANs VPNed together. I am happy with the setup and would not change it.
a) internet outages - these do occur - and usually not at the same time at both houses - with one instance one of the the houses would be offline, with two everything can keep running locally. Since they are VPNed together, I have ping sensors setup detecting the health of the other house, and then I get telegram alerts when a house is not reachable. And local automations keep working. As well as detection of power outages, hvac problems, leaks, etc.
b) HA updates - updates can be applied independently and tested locally, it’d be hard to known if the update has a problem at the remote house.
c) zwave - I use a lot of zwave, so the dongles are at each house.
I do use similar hardware and bias towards using the same devices to reduce variation.
The challenge of any HA system is configuration management; with 2 systems it’s more difficult. I want to have the same logic at both houses for similar devices (light automation, hvac schedules, door / window detection and alerting, etc.) So what I did is move my master configuration out of home assistant and I generate the HA config for each house via build scripts. So now bringing on a new light automation takes a minute and I can change the logic once and apply it everywhere. And I usually apply the config updates for each house when I arrive and typically do not touch the system at the other house.