Problem VBoxManage: error: Cannot register the hard disk ‘…’ because a hard disk ‘…/.vdi’ with UUID {…} already exists This error can also happen when trying to resize an .vdi image while it is still mapped to a VM. Analysis
VirtualBox could not start in Ubuntu
Problem VirtualBox does not want to start in Ubuntu. Error messages are: VirtualBox can’t operate in VMX root mode. Please disable the KVM kernel extension, recompile your kernel and reboot. Analysis . Solution First setup vbox: # sudo /etc/init.d/vboxdrv.dpkg-bak setup