Sometimes it’s happend that when you try to unmount an external disk the system gives you an error because it’s says that the disk result to be in use.
To check who blocks the disk you can type in a terminal:
fuser -um /media/disk
you must substitute /media/disk with your disk path
You can see in your terminal an output like this:
/media/disk/: 20471(user)
Which are respectively :
- disk's path
- PID of the process that block the disk
- user that run the process
With these informations now you can begin root and kill the process:
1 2 | su - kill -9 PID |
you must substitute the PID with your process' PID
English 
Italiano 
