There is a lot of conflicting information on the net whether it's possible to have more than one SharePoint server hosting SharePoint Central Administration site in the farm. I know for the fact that it's possible to have more than one server hosting SharePoint Central Administration site to provide high availability for that part of the SharePoint environment. Here is it can be done:
- Let's say you have two SharePoint servers: Server A and Server B. Server A hosts SharePoint Central Administration site, Server B doesn't
- To add SharePoint Central Administration site functionality to the Server B, run SharePoint Configuration Wizard on the Server B and at the "Completing the SharePoint Products and Technologies Configuration Wizard" step, click on Advanced Settings
- Select "Use this machine to host the website" to add SharePoint Central Administration site functionality and hit OK. Click Next to start the configuration wizard
- After the configuration wizard completes successfully, you will have additional server providing Central Administration functionality. To verify that it's in fact true, open SharePoint Central Administration site and under Farm Topology you should have Central Administration functionality listed under both servers.