Today I was trying boot2docker, and I was not able to start the docker engine, so I tried to run the virtual machine directly from VirtualBox and I saw that the problem was “VT-x is not available”. Searching in internet I found that this is because you don’t have the proper hardware (VT-x is not supported by your main board), or you have Hyper-V installed and active, this was my case.
So, when I would like to run docker I need to run this command and turn off hyper-v (this could also give you more performance, so if you schedule to don’t use VMs in your day work it’s good to have that supervisor disabled):
bcdedit /set hypervisorlaunchtype off
then you need to reboot, and yes it is boring!
The following command to turn it back on:
bcdedit /set hypervisorlaunchtype auto (or on, on my computer was set to auto)