Thanks, the performance issues i can see, maybe put test and development on one server and create seperate db instances.
The scenario is that we have a production CMS with a SQL backend feeding content to our web servers (the cms runs on the web server and the SQL backend feeds the content from a seperate server) The web team want to have a test system for both SQL and web server. I have already recommended a seperate web server on its own hardware (no VM here.. yet). This leaves the SQL server. I am cautious about allowing the test database on production hardware. Even though they will be seperate SQL instances, by its nature a test system may be less secure than live, could an insecurity in the test db down the live database or leave it vulnerable? As you say performance issues or downing the server will take out both.