Can't Unmount dev/sda3 (boot device)

Question

Please help a frustrated user.

I currently run only ubuntu 12.04: I cant seem to umount. I think the umount folder is lost. Tried all possible measures to no avail. Is there a way to force umount. I've been stuck with this umount issues for days now. I've already applied these but no luck: sudo umount /dev/sda3 I have equally tried umounting using gparted as well as utility :(

Solution

You can also try as root.

Step #1: In terminal type:

sudo -i

Step #2: In terminal type:

umount /dev/sda3

Sources: https://help.ubuntu.com/community/RootSudo

Comments

[Avinash Raj]

upload gparted screenshot.And what was the output of sudo umount /dev/sda3?

[Mitch]

Try sudo umount -l /mnt, or sudo umount -f /mnt

[easynhappy]

i tried uploading screen shots but appears i will need at least 10 reputations to do that. Gparted says: "the partition cannot be unmounted from the followeing mount points / Most likely, other partitions are also mounted on this mount points. You are advised to unmount them manually" When i used sudo umount /dev/sda3 it said " device is busy.

[Avinash Raj]

upload the screenshot to imgur.com and post the link here.

[easynhappy]

Here is the link to the screen shot imgur.com/edit

[Avinash Raj]

edit the image link.

[Avinash Raj]

plz post the screenshot link.

[easynhappy]

imgur.com/edit

[Avinash Raj]

i can't open it.Did you can?

[metroandgnome3arebrothers]

you are posting an invalid image link. right click on the image after uploading and choose "copy image location", then post that url here. I'm assuming you are using firefox, if not the steps will be slightly different.

[easynhappy]

I did but unfortunately, there is no option as 'copy image location'. Howerever everything that is in seen on the image can be summarized as: Gparted says: "the partition cannot be unmounted from the followeing mount points / Most likely, other partitions are also mounted on this mount points. You are advised to unmount them manually" When i used sudo umount /dev/sda3 it said " device is busy.

[easynhappy]

Gparted says: "the partition cannot be unmounted from the followeing mount points / Most likely, other partitions are also mounted on this mount points. You are advised to unmount them manually" When i used sudo umount /dev/sda3 it said " device is busy.

[metroandgnome3arebrothers]

have you tried the above "sudo -i", "umount /dev/sda3" it has more power than sudo, it also works well with the suggestion from Mitch eg "sudo -i" "umount -l /dev/sda3".

[Avinash Raj]

plz post the correct gparted screenshot link.

[metroandgnome3arebrothers]

the screenshow would be nice in order to see what paritions you have and which others are mounted.

[easynhappy]

Yes! i tried "sudo -i" "umount -l /sda3". But it says device is busy. Unfortunately, am not yet able to post screen shots here untill i get upto 10 reputations.

[Avinash Raj]

your problem will be solved only using the gparted image.so plz upload gparted screenshot image to imgur.com and post the link. the link will look like this i.imgur.com/gUPlF8O.jpg.

[metroandgnome3arebrothers]

omg that roller coaster is the coolest thing I've ever seen.

[metroandgnome3arebrothers]

This is powerful enough to unmount the OS partition and may cause a reboot: "sudo fuser -km /dev/sda3"

[easynhappy]

Thanks! Unmounted!!!!!!! sudo fuser -km /dev/sda3 helped :)

[Reaz Murshed]

sudo fuser -km /dev/sda3 unmounted the partition but everything goes black as it is the mount point of / I'm doing a data recovery as i accidentally removed my windows while installing ubuntu. Any idea?