There is a lot of talk about server licenses and how exactly it works. For each software license you acquire, you must assign that license to one of your servers. You can assign as many software licenses as you would like to one server but if you were to assign the software to more than one server you would be out of compliance.
One thing to keep in mind here also – a hardware partition or blade is considered a separate server, so would need its own licensing. Also, for each software license you assign, you can only run one instance of the software at any one time – this doesn’t include one physical and one virtual environment – its one or the other (which is why it is very important to be sure you have virtual employees logging into any server application).
If you need to reassign a software license you must wait at least 90 days before doing so. The only exception would be if you are having problems with the server and plan not to use it again.
No one said this stuff was simple!