I have an intel nuc running HA using the docker-compose method. It’s well away from the rooms I want to install my zigbee devices in AND it’s USB ports are already full of storage drives.
I’ve already setup mosquitto in the docker-compose file.
Can I install my new zigbee dongle (SONOFF Universal Zigbee 3.0 USB Dongle Plus Gateway) in a RaspberryPi with Zigbee2Mqtt elsewhere in the house?
Thats the beauty of MQTT, you can run Zigbee2MQTT on a separate device. Just point it to the mosquitto server and if you set it up correctly the devices would show up as normal in HA.
My Zigbee2MQTT install has never been on the same host as HA. As Charles said, MQTT makes it easy to separate them - you could have them on opposite sides of the planet if you wanted.
I concur with the other folks answers on the flexibility of Zigbee2MQTT placement, and it has a pretty low memory and cpu requirement in Docker as well. Also, I make sure my MQTT server on my main HA machine is always autostart and the first to start on my setup.
To your USB snakes nest, I bought a couple of these (link below) a while back and have been very happy using them to create storage for home stuff. There are probably newer versions since this one.
Good hunting and much success with your home automation adventure in 2024 and beyond!