I ran into a weird issue today while building my environment for a Windows Server 2003 course I will be teaching next week in BC. I wanted to use a vhd file that I had used previously successfully in Virtual PC. The first issue I encountered was the fact it is a differencing disk. In Virtual PC, there is no problem with this, if you have a VM associated to a VHD file which happens to have been made as a differencing disk, you get a prompt where you can simply point to the base.vhd file the differencing disk references and you are done. Virtual Server does things a little differently.
You need to configure the Master server from the administration website and include search paths as locations where your VHDs can be selscted from while configuring your individual virtual machines. Now in my case, I copied the base.vhd file to the same search path that my referencing VHD files were in. The disadvantage to this approach is that a second copy of the base.vhd file is needed. I have not yet attempted to add a second search path which includes the location of the base.vhd file. I will update this post when I try that if it works or not.
The second issue I encountered, was that while creating the new VM from virtual server administration website, I was unable to choose the option of using an existing virtual disk and point to the intended disk which was selectable from the previously configured search path. What I needed to do to work around this issue, was to choose the option of creating the new VM with no virtual hard disk file. Once this was done, I was able to go back and select the virtual hard disk file (using the same vhd file I had tried to select while creating the new VM) except when performing this step as a configuration task, it worked....
Go figure... Here's hoping that this post saves someone some time!