Force KILL State -D Process/PID in Linux

Solution 1:

When a process is in an "uninterruptible sleep" it's either waiting on I/O or it has encountered a bug. As with its name, it is indeed uninterruptible. You can wait for the resource to free up or help the resource free up, which will help the process state to change. Hopefully, it will be a state that will allow you to terminate the process.

It could also be potentially waiting on a resource from a parent process. With GNU ps, you can run using the f option to enable thread view.

fluxbox is a window manager, so it likely has X as a parent process. Try killing X before fluxbox.

Otherwise, the only realistic option is to reboot.