Maybe my question is not clear enough here. Let me restate that.
I have a 3.14 unity running. Now I would like to have the system be a fail-over system. BY reading the documentation, I understand I need exchange offbox. Fortunately, it is offbox exchange now. But I am still not clear the other things:Like how can I get a primary/secondary license key for the two fail-over server? What steps I need to change the existing server as fail-over server?
The primary license which you refer to is the standard license that every Unity server ships with. Therefore all standalone Unity 3.1(X) servers can be considered a primary.
If you wish to add failover you need to buy a failover license. The license (dongle) will have the same features as the primary; however the failover flag is marked.
If you already have a standalone Unity running and decide to add failover you do not need to reinstall it. You can run the failover config wizard to integrate it with the new failover server.
If you have another standalone/primary server that is already running Unity and now you would like it to become a failover server for a different standalone/primary, you would need to reinstall the machine you wish to make into failover server.
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.