As a keen Raspberry Pi enthusiast, I'am currently working on a Home Assistant deployment project on a 2Gb RPi-4B which may be of interest to other forum RPi fans.
Opted for the simpler ZHA/Docker SW installation running on a 120Gb SSD with USB-3/SATA interface, configured for USB booting.
Added a Sonoff Zigbee 3.0 USB Dongle to give access to my Zigbee devices.
Installed Mosquitto Broker, InfluxDB database, nodeRED and Grafana from within Home Assistant, all integrated very easily and ran without issue.
Initially ran the setup on my RPi-3B+ but found that it was unstable and periodically crashed, probably due to lack of RAM, since migrating to my 2Gb RPi-4B have not had any issues.
Having previously configured my smart home devices, energy monitor & recorder etc outwith Home Assistant, have been very pleased with the HA experienced, very easy integration with all my Wi-Fi and Zigbee devices, great GUI, very easy to achieve any desired device integration.
Excellent 3rd party support as HA is very widely used world wide.
While any Wi-Fi or Zigbee device can be very easily configured within HA, I find that configuration via nodeRED is easier, more versatile and integrates perfectly.
Have even managed to integrate my Drayton Wiser smart heating TRV's into the system to monitor and record room temperatures having given up on these as zone control devices, now (rather expensive) room temperature stat's!
Have retained the Drayton Wiser Hub to provide a Wi-Fi interface with the RPi using a 3rd party SW utility, could directly Zigbee interface with the TRV's without the Wiser Hub but find the Hub Wi-Fi interface is more versatile and reliable.
The "dashboard" displays within HA are excellent with lots of addons and 3rd party utilities available.
For more complex recording and graph displays I use Grafana/InfluxDB which is very easy to configure and use within HA.
All in all a good project which I'am still populating, have enjoyed the experience, highly recommend Home Assistant which appears to run very well on a RPi-4B, in my case with 2Gb RAM.
Have not tried running on an SD card, for such a project likely would be foolish considering the finite life span of even a top of range SD card.
