How can I umount /dev/sda1 partition in ubuntu?

Question

I have a Ubuntu VM which has an unmanaged OS disk associated with it.

I want to shrink my OS disk of size 50 GB to 40 GB. However, when i try to unmount /dev/sda1 partition it tell me

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

Therefore, i am unable to unmount it and then shrink it. Could anyone please help me with this?

make sure no process has file handles from the partition open. you can use `lsof` to check for open files. — Gerald Schneider, Feb 10 '20 at 15:39
Use lsblk to see the mountpoint on /dev/sda1 (apparently /mnt). And do **fuser -vM /mnt** to see processes. — Gerrit, Feb 10 '20 at 15:56

Romeo Ninov · Answer 1 · 2020-02-10T16:14:13.703

0

Seems like your disk /dev/sda1 is mounted. So the best you can do is to boot from live CD and then do the operations you want to do. When boot from live CD /dev/sda1 will not be mounted.

Of course you can start to search for processes which keep open files in this filesystem. But this can take a lot of time.

edited Feb 10 '20 at 16:14

answered Feb 10 '20 at 15:49

Romeo Ninov

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The error message states that the partition is mounted in `/mnt`. – Gerald Schneider Feb 10 '20 at 15:50
@GeraldSchneider, clarified – Romeo Ninov Feb 10 '20 at 16:14
How can I boot my Virtual machine from live CD? Can you suggest me any article. – Sameer Keluskar Feb 11 '20 at 11:53
@SameerKeluskar, what is your hypervisor? – Romeo Ninov Feb 11 '20 at 11:54

How can I umount /dev/sda1 partition in ubuntu?

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