while starting my VM using vagrant, I have following error :

The guest machine entered an invalid state while waiting for it to boot. Valid states are 'starting, running'. The machine is in the 'poweroff' state. Please verify everything is configured properly and try again. **If the provider you're using has a GUI that comes with it, it is often helpful to open that and watch the machine**, since the GUI often has more helpful error messages than Vagrant can retrieve. For example, if you're using VirtualBox, run `vagrant up` while the VirtualBox GUI is open.

So, I edit my Vagrantfile and uncomment gui

   config.vm.provider "virtualbox" do |vb|
     vb.gui = true
   end

Then I start my vm using VirtualBox. I have the following error : VT-x is being used by another hypervisor … Please disable the KVM

what to do ?

1. see if kvm is running and is used

witr@serv:~$ lsmod | grep kvm kvm_intel 143592 3 kvm 459835 1 kvm_intel

here kvm is used by one consumer (kvm_intel) and kvm_intel is used by 3 consumers.

1. stop kvm consumers In my case it’s the android emulator i have launched from AndroidStudio which causes problem. I stop emulator.

2. restart vm that’s all