Hey everybody,
We've seen this behavior in two of our virtual servers. Seemingly every few weeks I'll get an alert from our monitoring system that our servers volumes are low on space. The culprit is always shadow copies on the server. I set limits on the shadow copies through the volume properties but it seems the settings revert back to no limit after a random amount of time.
ESXi version 6.0.0
Windows Server 2012 R2 Standard - Running a SQL Express server
Windows Server 2016 Standard - Domain controller