How can I compare two VirtualBox snapshots?
Mount each VDI as a logical drive on the host. Use a folder comparison tool like Beyond Compare to compare each logical drive.
I have not tried this and it would take much effort to test it out, so I'll just let you know what I'm thinking. I use Linux almost entirely here.
A tool such as this or other checksum tool can checksum every file on your VM filesystem's snapshots.
http://md5deep.sourceforge.net/
Apparently certUtil is built into Windows and can do checksums too. md5 might be a little slow - it may be worth while looking into finding the fastest checksum tool/algorithm for your OS. You can completely skip doing checksums if you don't care whether or not a file has changed.
I'm sure there would be a little work on your part (making a batch file) but the idea is:
On each snapshot
- Get a list of every file/directory
- Checksum each file
- Save all gathered info to a file
Afterwards, compare the two files with diff (GNU) or FC (Windows), etc... to see what files were added, removed, moved or changed.
That's my 2 cents. Here's someone else's that might help, I'm not sure.
https://improvingsoftware.com/2013/09/09/how-to-diff-two-folders-from-a-windows-command-prompt/
It references RoboCopy for creating diffs and Beyond Compare