I would just like to know if I want to install Fast Search for SharePoint 2010 on a separate server then the SharePoint Farm servers. Do I need to install SharePoint 2010 on the Fast Server itself? Is it mandatory? If no is it recommended to isntall SharePoint on Fast Server?
For production enviroments the answer is:
SharePoint and FAST run on dedicated boxes and are not installed side by side on a server.
For development and demo porpose it is ok to run everything from one box.
Please review Hardware and Software Requirements here: http://technet.microsoft.com/en-us/library/ff381239.aspx
The text below is taken from it:
Install FAST Search Server 2010 for SharePoint on a server that has a clean installation of one of the following:
Windows Server 2008 SP2 x64. All regular Standard/Enterprise/Datacenter versions are supported.
Windows Server 2008 R2 x64
The server must be fully updated with the Service Pack and updates and restarted before you install FAST Search Server 2010 for SharePoint.
*Do not install FAST Search Server 2010 for SharePoint on a server that runs a Domain Controller.
You can install the two on the same server, but you wouldn't want to in production. FAST is designed to use every bit of free memory and performance available. From speaking with one of their engineers, they see idle CPU / Memory as a waste of your hardware.
Its fine in dev. You install the FAST Server, configure it to talk to SharePoint via 2 Service Applications; a content SA and an Query SA.