To generate a memory dump, press Scroll Lock + Scroll Lock while pressing and holding right-CTRL. For more information, see the Microsoft knowledge base article 244139.

Note: You must press right-CTRL for the memory dump to occur. Pressing left-CTRL does not work.
To configure a Windows virtual machine to allow manual memory dumps, see http://msdn.microsoft.com/en-us/library/ff545499.aspx.
This process works the same on both physical and virtual servers.
The tool the Microsoft engineer was talking about is vmss2core.exe and it ships with VMware Workstation. The procedure is:
  1. Create a snapshot of a virtual machine with the ‘snapshot the virtual machines memory’ option selected.
  2. Browse to the virtual machine’s folder on the VMFS or NFS volume and download the ‘-snapshot1.vmsn’ file to a temporary directory.
  3. Copy the ‘vmss2core.exe’ file from a VMware Workstation installation to this temporary directory.
  4. Run the following command (where ‘w2k3test01-snapshot1.vmsn’ is the name of your snapshot file):
vmss2core.exe w2k3test01-snapshot1.vmsn -W

This process creates a memory.dmp file in the current directory. This file can be analyzed to determine what was running at the time of the snapshot creation. Note: the vmsn file is slightly larger than the amount of vRAM allocated to the virtual machine and the memory dump is equal to the amount of RAM installed. For a VM with 8GB of RAM you’ll need at least 16GB of disk space to complete this process.

How can I open the memory.dmp files to verify they are working?

You only need to download and install two applications (note: a few dependencies exist for these apps, such as the .NET Framework).

Download and Install Debugging Tools for Windows
Download Windows Symbol Packages

These downloads are free and give you the tools to open/review a crash dump.