Google Fu: Shutting Down Proxmox when you get a file lock error

Sometimes, Proxmox becomes unable to shutdown a VM. This is far more common if your OS doesn’t have the Qemu agent installed. To fix this:

Open PVE shell

rm /run/lock/qemu-server/lock-102.conf
qm unlock 102

For a script, see # How to: Fix Proxmox (PVE)

Or, use glances (see Process Monitoring Tools and find the running kvm and kill it.