can you please tell me where you got this information?
I talked to several Cisco engineers and they told me they had no idea where this concept is coming from, but it does not work that way. You can enter the list of CUCM's but the first one will be used only.
I checked the documentation (for instance, the Configuration Guide for ICM 8.0(2)), but there was no information about this failover option.
as far as I know, it cannot be done. You configure one CUCM for the Side A Agent PG PIM and a different CUCM for the Side B Agent PG PIM.
I must admit I have heard this option, too, and it somehow seemed to work with ICM 5.0 (if I remember correctly). But it definitely did not work with 7.0 and 7.5. So if it is a feature, it must be undocumented.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.