Here's what's going on. It could help you if you opened the VirtualBox Media Manager (Cmd-D by default) and follow this. Just navigate to your VM and expand all the children.
You'll see that the "Snapshot 3" ({34e3a9b1-...) has two children (I'm cutting several digits, for the sake of clarity):
- {d33d19b7..., and
- {26d9b538
You can also see that in the part of the .vbox file that contains a list of the VDIs and you can see that they're in the same indent level, i.e. they're both children of the same parent (the red arrows don't actually exist in the .vbox file, neither is the text bold for that matter):
<HardDisks>
<HardDisk uuid="{eeb7130f-...}.vdi" format="VDI">
<HardDisk uuid="{92c22099-...}.vdi" format="VDI">
<HardDisk uuid="{34e3a9b1-...}.vdi" format="VDI">
>>>>>> <HardDisk uuid="{d33d19b7-...}.vdi" format="VDI">
>>>>>> <HardDisk uuid="{26d9b538-...}.vdi" format="VDI">
</HardDisk>
</HardDisk>
</HardDisk>
</HardDisks>
Now, the "
{d33d19b7-...}.vdi" in your filesystem is
exactly 2 MB (2097152 bytes), which means that it's an empty, unused VDI. This must have been created when the snapshot process crashed. Which means pretty much that it's useless (at this point) and you can safely remove it. BTW, the crash happened at 03:50 in the morning?
So, in the VirtualBox Media Manager, select that "
{d33d19b7-...}.vdi" disk and select Remove. You might be asked if you want to delete the file, select Yes.
Now, I've noticed that you take your snapshots while the VM is running. It's not a great idea. Unless you're really familiar with how snapshots work, I'd try to learn a little bit more before going live snapshot, after live snapshot, after live snapshot, after live snapshot. If anything goes bad during
any of the steps, your VM might not be repairable. Not that VirtualBox crashes when taking snapshots, but I think you got really lucky this time.