I assume this means that you were using Vmware Workstation? The VDDK is for Vmware vSphere, which -IIRC- runs on Linux and coordinates computers running ESXi, which are where vSphere VMs actually run.
Not that many people are going to be using Vmware Workstation to run a large number of VMs.
And I was like... what virtual host?
What I found was Server 2003 running on VMWare Workstation, running on a Windows 7 Dell PC sitting at the bottom of a rack.
A lot of people think VMWare Workstation is the pinnacle product of the company and I have NFI how this came to be.
Sure, a type-1 hypervisor like vSphere is technically better since there's no host OS creating unmanageable contention and if you have guests with higher performance requirements then yeah it's settling for something half-assed.
But in reality, we have some similar shit to a "fax server" that has manually set up weird manufacturer printer settings (local admins tried to be automated/distributed) and old third-party software libraries that "infects" a system globally (2 versions of that library cannot co-exist on a computer).
If that piece of crap can be contained on a VM, as long as it's contained and keeps trucking after a restart/powercycle everyone is happy. What kind of VM container hosts it is really secondary.
(What the software in question is can probably be inferred from the comment, the software is liked by users at the client so it's not going away)