Snaps don't actually work that way. Snaps are squashfs images, which imposes the contract of requiring to unmount the old image before mounting the new one. Whe

Snaps don't actually work that way. Snaps are squashfs images, which imposes the contract of requiring to unmount the old image before mounting the new one. When files are in use, you can't easily unmount. (Yes, you can use a lazy unmount, but bad things happen on the system with those, so it's not a good idea to rely on it!) I think you're thinking of Flatpaks, which are basically hardlink/reflink farms with symlinks used to control the pointers to the current version (OSTree).