First decide where everything should be installed. Once the support and core components are installed, using Retain is the same no matter what platform it is installed on.
VMware Support
Retain Component Locations Dictate Resource Needs
The Number of Users Affects Resource Needs
Minimum Retain System Requirements
Single-Server RAM
Separate Database Server RAM
Separate Index servers, Database server, and Retain Server
Securing the Database Connection
High Availability Indexer Requirements
Software installed by Retain
Linux Server
Windows Server
SQL Database
Browsers