Unable to launch VirtualBox after host space was empty

[TsinghuaBoiler]

Dear all,

My host ran out of space and I reboot it. But then when I tried to launch VirtualBox, its said:

"Document is empty.
Location: '/home/zengroghao/.config/VirtualBox/VirtualBox.xml', line 1 (0), column 1."

I checked the file above, and it was empty. But there was another file named "VirtualBox.xml-prev" with contents. So I backed up the "VirtualBox.xml", and renamed "VirtualBox.xml-prev" to "VirtualBox.xml", and launched it again. Then the VirtualBox Manager existed, but there were no virtual machines listed.

Could anyone kindly tell me how to fix without loss of data stored in my virtual machine?

Thank you!

Zengrong

[socratis]

Did you clear some space in your host? Otherwise you're going to run into the same problem again.

The "VirtualBox.xml" is the registry of the existing machines, plus the general VirtualBox preferences (networks, DHCP servers) and the VBoxManager preferences. No big loss.

Your VMs are another thing and they should be (theoretically) in "/home/zengroghao/VirtualBox VMs/" or something like that. In there, there should be folders corresponding to your VMs. In each folder there should be a ".vbox" file. That's the recipe of the VM. Double-click on it and it will register the VM in VBoxManager. Or register it by going to the menu Machine » Add...

[TsinghuaBoiler]

Dear Socratis,

I clicked the vbox file following your advice, and it works!

Thank you so much for your help! It makes me much clearer about virtual machines.

Thank you,
Zengrong

[socratis]

Nice.
Just put a monitor on your host that checks the available hard disk space...