One SQL Server Instance, Two Server Names

Question

I am in the process of retiring legacy Microsoft SQL Servers and I have an opportunity to retire one of my existing SQL servers, SQL Server X, if I migrate the remaining databases on it to another server, SQL Server Y. Unfortunately, there are still numerous undocumented processes that reference SQL Server X that I cannot afford to break at this time. Which leads me to this question:

Is it possible to make SQL Server Y continue to work as it does today without changing it's name AND somehow make the old name for SQL Server X into an alias for SQL Server Y?

The goal is to remove one server from my domain and make another server accept SQL Server database connections as though it were the original server. This would buy me a few months of time before I finally retire both servers for good. It seems conceptually possible since computer names are already aliases for IP addresses, but can this actually be done to a SQL Server database instance name.

Answer 1

Use a DNS CNAME entry that resolves ServerX to ServerY, This is OK where you have the same instance name or you have default instances.

To deal with instance name differences, then you can use 2 concepts:

• Use client aliases which hide the serverx\instancex
• Use "server,port" to avoid instance names

Finally, you'll need to have netbios aliases if some process expects to map a drive to the old server.