When does a VirtualBox snapshot actually happen
No, you don't have to wait until a snapshot has created completely. The VirtualBox documentation sheds some light on the technology behind snapshots:
When a snapshot is taken, VirtualBox "freezes" the [virtual disk - I.K.] image file and no longer writes to it. For the write operations from the VM, a second, "differencing" image file is created which receives only the changes to the original image.
You can read more about it there:
- http://www.virtualbox.org/manual/ch01.html#snapshots
- http://www.virtualbox.org/manual/ch05.html#hdimagewrites