We have a request to physically rename the servers. What is the procedure in case of redundancy?
Physically renaming the server will not affect redundancy in any way. The important thing is the KernelName item in the Redundancy branch of the registry. If you use /RF, IpAddr1 and IpAddr2 items in registry are also important. But if you have symbolic names there, then of course you have to change them.
And of course, if you have the server names in ODBC (Application.ServerName.Syscfg), they must also be changed.