Hello,
I assume that you have an,
Existing vMM1 --> x.x.x.1/24
Existing vMM2 --> x.x.x.2/24
VRRP IP --> x.x.x.5/24
New vMM3 --> x.x.x.3/24
New vMM4 --> x.x.x.4/24
All the configurations are going to be in L2 VRRP redundancy. (Even for L3 we can still follow the below process, in DC/DR kindof setup.)
I understand that you are having an issue of spec sizing with the existing MM setup and your upgrading process is dragging on because of it.
If the Configuration on the MM is fine. we can add one New vMM3 as another Standby and bring down (remove with different IP or replace with same IP) one of the existing vMM1/vMM2.
The configuration will be shared with the new vMM.
Please remmber you don't have to worry about bringing down the MM, as long as there are MCs to take care of the APs and Clients.
I believe, we can bring up more than 2 nodes as MMs as we are leveraging the VRRP feature, if it is true we can try the below steps:
-Hope you have configured the IPwithPSK as the authentication for the IPsec between the MM and MCs
-Also I hope you have pointed VRRP IP as the MM IP in the MCs
-Even if you have mentioned the Physical IP as the MM in the MCs, while bringing up the New MM3 in the network remove the standby
-Make sure you have the same set of configurations on the New MM3 before proceeding to the New MM4
If bringing more than 2 nodes as MM is not possible, we can remove the standby then add the MM3 as the standby. Then after confirming that configs sync is successful we can proceed to the MM4.
The New MM Active MM Controller should come up with the same configurations (atleast MC folder, WLAN/AAA profiles and VLANs) as the old controllers to prevent any unfortunate incidents in the network.
But, the above steps will not require down time for the network but only for the MM setup.
If you are still not sure, please share the above steps with TAC, if no response from @Westcott.
Please keep us posted about the result.
Hope this helps you!!
- Jeeva Selvakumar