Domoticz

I use a Domoticz installation with Conbee-II controller. I am thinking about setting up a second Domoticz on another server, with another gateway.
Would this work? Would I be able to control all devices from both servers?

Nope... afaik zigbee doesn't have the option to have a second controller in slave or otherwise skbthe second domoticz system would have to control the devices via the first domoticz installation.

You could use remote sharing so you can control the devices of the conbee Domoticz from the remote Domoticz.

But then , why do this as you can also accès the conbee Domoticz directly from a remote location.

Why do you want to use another zigbee controller in your home?

Actually, I am in the process of migrating to Buster.
Since my setup has become quite complex over time, I want to take it step by step: I have a separate Pi4 with SSD on it, so I can take it one step at a time.
It would be nice if I can test the new setup while the old is still functioning. This would mean two Zigbee routers. But I understand this is not an option...

This would mean two Zigbee routers

Nope, 2 coordinators (or Gateway). You can have plenty routers, but only 1 corrdinator in the same zigbee network.

Since my setup has become quite complex over time

You mean the whole domoticz or your zigbee network ? Because you can use 2 domoticz and only 1 deconz instance with the conbee (if you are using deconz ?) deconz is working in stand alone mode and all applications can connect to it in same time. (If I m right Z2MQTT work same)

But having 2 zigbee network is not a good idea, it work but not the better solution, zigbee is a meshed network, better to have one bigger than 2 smalls.
And migrating devices one by one is not a good idea too, some brands don't moving in the network, so better to install all routers then all sensors.

Thanks for all the tips.
I am not trying to set up a second Domoticz for permanent use, just one to take time pressure away from migration.
A complete and fully functional copy of my prod version, so to speak.

I think it will be sufficient to have a separate Zigbee network with one single end device to prove that ZIgbee is installed correctly. So I guess I'll go that way...

I am using a second RPI. The first shares its data with the second. Both on Bullseye.
When I switch on the second, the switch on the first is activated.
When switching on the first it is reflected on the second.
It works with RFXTFX, WiFi and sysfs.

I realise that, but it was not my question
..