virtualbox.org

AllenL wrote:It was mentioned above that the .sav files are created during snapshots and must not be deleted.

If they are used as part of the snapshot and you want to revert to that. For example, if you take a snapshot of a live VM, you'll have a Α.sav file. If you take another one at a later time, you'll have a B.sav. If you want to revert state A, you'll still need the first A.sav.

Since you merged them, I don't think you do, but I would simply quit VM and VirtualBox and move the Snapshots directory somewhere else. If it works, you know you can delete them.

AllenL wrote: If I have merged all snapshots into one flat file (no more snapshots), can I now delete the .sav and the rest of the other snapshot files in the folder?

You'd first have to explain how you did the merge, because if you did it the normal way then VirtualBox should already have deleted any redundant files.