Use SQL Alias for your SharePoint deployment !

Once the farm is installed, it’s difficult (but possible !) to change the database server name. SQL Alias provide an easy way to do that.

Alias must be define on each farm’s server. you can do that using the command cliconfg in a command prompt.

In the application, add the TCP/IP Protocol on the right column and click the Alias Tab

Click on the Add button to add a new TCP/IP Alias. the field Server Alias is used to define the name you will use in the SharePoint configuration. Server name is the real server name.

When the Database server change, you just need to update your alias on each farm’s server.