Linux – Ubuntu Linux froze in VirtualBox


I am working on the newest version of Ubuntu Linux on VirtualBox under a 64-bit Windows 7 host. When I was working, VirtualBox froze, and I hadn't saved my work in Ubuntu. What should I do?

(This happened after I installed the extension pack for USB 2.0 and I went ahead and tried to access a USB port. I suspect that this led to my current situation.)

Best Answer

There are two ways Virtualbox can "freeze". One is that the guest OS (i.e. Ubuntu) or the kernel mode VM code is not being scheduled or is locked up. There's not much you can do in this case.

If it's the GUI that is freezing (happens quite frequently if due to display driver or other bugs), you might be able to access your guest OS through SSH or VRDP. Of course you must have these setup before the freeze occurred.

If not, you can try your luck with the vboxmanage controlvm command. Use the savestate function to store the current OS state to disk, and then you can close the crashed VBox and open it again.