A colleague asked if I had a script lying around that could investigate datastores and find orphaned files.
Well, I didn’t. But instead of spending a lot of time creating one from scratch I went to our friend google and searched. There were lots of results, but I found one from Powershell guru LucD (lucd.info) and stopped searching.
The script and instructions are found here: http://www.lucd.info/2016/09/13/orphaned-files-revisited/
Be aware that the script, or more precisely a VMware VIM method that the script uses, is relatively slow.