We like these sort of customers, as they keep us on our toes. I've tried to find some other process or service I could stop - any way at all to stop the in-progress snapshot.As happens sometimes, our more technically minded customers question a system that “just works”. Of course there are always some risks involved in that kind of shutdown. The only way out that I've found is to shut down or reboot, and this never completes cleanly - I have to ultimately kill my virtual machine (which is the same as a normal Windows shutdown hanging, and then pressing the power button to finally shut down). I may be misremembering this, but I think if I kill Reflect.exe, the UI disappears (the window that shows the backup progress) but ReflectBin.exe keeps running and I cannot kill ReflectBin.exe. In Task Manager, I see a Reflect.exe and a ReflectBin.exe. (There are other cases where the Mac goes to sleep in the middle of a Reflect backup, but as long as it is beyond the snapshot phase, the backup just continues from where it left off.) This just seems to be a timing glitch if my system is making a snapshot precisely when the Mac goes to sleep. I don't think there is anything wrong with VSS in general, since 90% of the time, my backups and images work just fine.

There is no Cancel button, and I have not yet found a way to cleanly abort the backup process. When I wake the Mac, I find Windows running normally, but the backup is stuck in the 'creating snapshot' state. (The Windows VM was then put to sleep like any other Mac app - it's not the same as Windows itself entering a sleep a standby state.) I believe this happens when the backup had started but then my Mac went to sleep. Once in a while I discover a file backup is hung during the VSS snapshot phase.

Macrium reflect vs drive snapshot