Today i had the problem, that my vagrant box could not be started with "vagrant up" and also destroying or halting the box did not work.
The process was terminated with the following error:
The problem in this case is, that another vagrant process is running. If you are sure, that you can terminate the running vagrant process you can kill it. To do this you need to find out the process id:
The relevant process, is not the first one in the list, because this is the grep itself. The relevant one is the process with the id "576". We can now kill this process.
After killing the running process the box should be unlocked and "vagrant up / destroy / halt / ..." can be used as usual. What is usefull next, depends on the state of the box.
If you want to learn more about Vagrant and Chef, you can read our HowTo "DevOps with vagrant and chef"