Discovery Accelerator 8.0 SP3 - DR best practices

Hi

Is there any Best practices documentation available for implementation of DR server for Discovery Accelarator  8.0 SP3? I googled the forums, most of the docs show implementation of DA but not much info available on HA and DR.

We are planning to install 3 DA servers with hot spare VM available in data center, I need to know what are the steps to switch over to other server in case one of the servers goes down.

Thanks in advance

Rajesh