解决vagrant启动机器时报告session locked问题

今天使用vagrant up启动一个虚拟机时，一直卡住，Ctrl + C后再次运行，却报下面的错误

There was an error while executing `VBoxManage`, a CLI used by Vagrant
for controlling VirtualBox. The command and stderr is shown below.

Command: ["modifyvm", "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "--natpf1", "delete", "ssh"]

Stderr: VBoxManage: error: The machine 'miu_centos_65_64_default_1463116943' is already locked for a session (or being unlocked)
VBoxManage: error: Details: code VBOX_E_INVALID_OBJECT_STATE (0x80bb0007), component Machine, interface IMachine, callee nsISupports
VBoxManage: error: Context: "LockMachine(a->session, LockType_Write)" at line 462 of file VBoxManageModifyVM.cpp

There was an error while executing `VBoxManage`, a CLI used by Vagrant

for controlling VirtualBox. The command and stderr is shown below.

Command: ["modifyvm", "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "--natpf1", "delete", "ssh"]

Stderr: VBoxManage: error: The machine 'miu_centos_65_64_default_1463116943' is already locked for a session (or being unlocked)

VBoxManage: error: Details: code VBOX_E_INVALID_OBJECT_STATE (0x80bb0007), component Machine, interface IMachine, callee nsISupports

VBoxManage: error: Context: "LockMachine(a->session, LockType_Write)" at line 462 of file VBoxManageModifyVM.cpp

怎么办呢? 经过搜索后发现一个解决方案，运行下面的命令后即可解决。运行时请注意将uuid替换成自己出错时显示的uuid。

vboxmanage startvm xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx --type emergencystop

1	vboxmanage startvm xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx --type emergencystop