Virtualbox - Failed to open a session for the virtual machine

Question

I installed VirtualBox via Software Center. When I try to load a VM, getting an error exactly like this:

Error window

After I googled this error, found many different solutions, none of them were helped my situation. Also I removed all packages associated with VirtualBox, then downloaded and installed the latest package which I downloaded from Oracle repositories. Nothing is changed.

Additional Information:

OS : Ubuntu 12.04 64-bit
VM : Linux Mint 14 Cinnamon/MATE 64-bit

I created new vdi disk and tried to start it from .iso image.

Virtualbox Settings:

Num of processors : 4
Memory : 512 MB
Video Memory : 128 MB
3D Acceleration: Enabled

score 2 · Answer 1 · edited Apr 13 '17 at 12:23

2

The error message is pretty self explanatory. The VM you are trying to start needs hardware virtualization enabled. See the follwing Q&A on how to do so (provided your CPU is capable of this):

How do I enable hardware virtualization technology (VT-x) for use in Virtualbox?

If this does not resolve the issue, the following steps may help:

Reboot the host OS
Try with fewer virtual CPUs starting from 1 only
disable VT-x settings in VBoxManager (reported to worked but I doubt this)
on a Hewlett Packard machine hardware VT-x could only be achieved with a BIOS update (source superuser.com)

edited Apr 13 '17 at 12:23

Community

1

answered Mar 04 '13 at 09:31

Takkat

142,284

it's already enabled. – talha06 Mar 04 '13 at 09:33
Please add this valuable information to your question. In addition we also may need to know the architecture of host and guest and where the VM you try to start comes from. – Takkat Mar 04 '13 at 09:41
ok, edited question; more information is added.. – talha06 Mar 04 '13 at 09:46

score 0 · Answer 2 · answered Jun 20 '18 at 05:48

Click "Discard" (Discard the saved state) option (option from the virtual box manager) and try starting the virtual box once again it must work . this usually happens when your host operating system sleeps while your virtual machine is still active . Please note any unsaved data will be lost .

score -2 · Answer 3 · answered Jan 05 '14 at 17:22

-2

Yes, for me that was the issue. Run the VB as an administrator. Right click on the VB, and select "Run as Administrator"

answered Jan 05 '14 at 17:22

user232101

1

1

That looks like a Windows "solution" - in any case never run VirtualBox (or VMWare) as root/administrator. – guntbert Jan 05 '14 at 19:23

score -3 · Answer 4 · answered Aug 16 '13 at 14:55

-3

It's that you need to run Virtualbox as an administrator.

answered Aug 16 '13 at 14:55

Samaritan

1

3

Never run virtualbox/vmware as root! – guntbert Aug 16 '13 at 15:13

Virtualbox - Failed to open a session for the virtual machine

4 Answers4