Is the cluster split between 2 data centers? If 2 data centers I would consider 2 separate pilots to have control of which server is used by which users and build load balancing.
I personally like to use 2 Groups per UCON Server and split it between separate CUCM groups, this way if one of the primary CUCM server goes down not all ports have to re-register at the same time, but if all servers are at the same data center this would be an overkill.
I would create at least 2 device pools. For example: Primary CUC assigned to device pool for media devices in data center "D", Secondary CUC assigned to device pool for media devices in data center "P"
The CM group and assignment may have other considerations for you...such as how you're trying to distribute devices across CM's, failover and tertiary failover considerations, and etc. I would want the Primary CUC ports to register to a subscriber in the same data center (i.e., D). The same would be true of the Secondary CUC ports (i.e., P).
IMO, 2 port groups are fine - 1 for each server. Assign the servers based on your CM group selection.
It really depends on the physical location of the servers as far as the device pools go. Let's say you have 1 server in Site1 and the other in Site2. In that case, I would generally have a device pool at each site for media / applications:
CUC Primary at Site1 would be in Site1_Media_DP
CUC Secondary at Site 2 would be in Site2_Media_DP
In CUCM, I would have 2 line groups - one for the CUC Publisher and one for the CUC Subscriber with a single hunt list. The priority of the line groups would be:
In a Unity Connection cluster, you want the Subscriber to be the primary call processor and then you can overflow to the Publisher ports (if required) during peak call volumes. Just remember that if you have ports that are solely dedicated to MWI (i.e., they do not answer calls...then do not add them those ports to the CUCM line groups).
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...