How can I install OS X Server as a VM after downloading it from the App Store?

Dave,

Unfortunately you did not provide information about your hardware setup, so I will assume that you have sufficient capacity to accomplish what you want to do.

The modern Server application from Apple, is an app that activates and provides a GUI (Graphic User Interface), to manage the underlying OS X as a server with specific capabilities. It has been developed with the sole purpose of managing Apple Software.

To virtualise Server, you will have to do at least the following:

1. Have the hardware capable enough to handle the load.
2. Have OS X installed on the hardware (Apple HW) and partition said HW Storage to have Data separated from the OS SW. (Plan OS, Virtualisation, Data)
3. Install the virtualisation software.
4. Install the OS in the virtualisation SW on which Server will run. (Could be again OS X 10.11.5 of even Snow Leopard or any other)
5. Download and install Server.
6. Configure Server and Data usage.
7. Activate the required services.

HTH

Leo

As some additional clarification to Leopardus' reply.

• You install VMware Fusion in to your Macs existing copy of OS X
• You use VMware Fusion to create a VM
• You use VMware Fusion to install a copy of OS X in to the VM
• You then copy the Server.app you purchased in to the VM
• You then run Server.app inside the VM - Server.app will then configure that copy of OS X to act as a server

Different versions of OS X need different versions of Server.app. The only version of Server.app you can current buy and download is the version that requires running in El Capitan and is currently Server.app 5.1

If you an original and now very old copy of the Snow Leopard Server DVD then you could also install that in to a fresh empty VM in VMware Fusion. This unlike Lion, Mountain Lion, Mavericks, Yosemite and El Capitan does not use the current Server.app approach it is instead a special server version of OS X.

While as standard you cannot get older versions of Server.app and also as standard cannot get Snow Leopard Server anymore if you really must there are legal ways.