You are done using your external memory disk (say-KINSTON Pen disk) in Linux and you want to unmount it. But you get an error message like "umount: /media/KINGSTON: device is busy". Which of the following you can use to UNMOUNT IT SAFELY.
Find the process that is using the drive and kill it safely.
option a is correct and the following needs to be done to implement it: fuser /media/KINGSTON;fuser -k /media/KINGSTON; umount /media/KINGSTON
Option a is incorrect and unsafe and you need to hard boot to solve this problem.
Use a force option on unmount to acheive this : umount -F /media/KINSGTON
a and b are correct.