umount: /: target is busy

Question

When I ran the command

umount /dev/mapper/ubuntu--gnome--vg-root I I got :

umount: /: target is busy
        (In some cases useful info about processes that
         use the device is found by lsof(8) or fuser(1).)

I tried some different options with the command lsof and fuser, but it didn't work so far.

Does anyone have any idea how to resolve this issue?

Solution

Please try this commands:

umount -l /PATH/OF/BUSY-DEVICE
umount -f /PATH/OF/BUSY-NFS(NETWORK-FILE-SYSTEM)

Reference: https://stackoverflow.com/questions/7878707/umount-a-busy-device

Comments

[Admin]

How could I find the path of busy-nfs?

[Lv1z]

That command (-f) stands for --force, check the link, the author put it that way but you can use the path of your busy device. Also: oletange.blogspot.com/2012/04/umount-device-is-busy-why.html

[Sridhar Sarnobat]

my autofs nfs share still hangs when I use -f

[Konrad Gajewski]

umount -l worked for me. Thx.