An important consideration for making a SharePoint farm highly available is what to do with Central Administration. By default, Central Administration runs on the first server in the farm. Although you can move Central Administration to a new server, even if the previous server running Central Administration is unavailable, some additional, manual intervention will be required. During this time, no other administration tasks can be performed with Central Administration if it is unavailable.
You can install Central Administration on more than one server in the farm in order to alleviate this issue. The easiest way to achieve this is to run the SharePoint Products and Technologies Wizard and in the advanced options for Host Central Administration Web Application, select the option to Use this machine to host the web site. Optionally, you can also implement NLB for the Central Administration web application, if you require load balancing or automatic failover for Central Administration.