Representing Servers in Team System's LDD

Lately, I’ve been asked the following question more than once: “Using the Logical Datacenter Designer, how would I place the database on the same server as my web server?”  Well, this is a great question and exposes a problem in the way we are communicating what the LDD is supposed to represent.

First – with the LDD you CAN NOT represent a web site and a database server on the same logical server. 

The Logical Datacenter Designer is used to create diagrams of interconnected logical servers that represent the logical structure of a datacenter.  They key here is the term “logical server.”  When people are asking if they can put IIS and SQL on the same machine – they really are working with two Logical Servers – IIS and a Database Server. Logical Servers represent application hosts in the datacenter.  How these logical servers are configured with regards to where they are installed is really a “physical” characteristic.  When using the LDD you are really specifying the Logical Servers (some may see these as services such as IIS Web Server, SQL Server, etc).