my ubuntu system crashed after changing ownership of use directory and I am unable to change back ownership to root

Question

I by mistake ran the command

sudo chown -R myname:my name /usr

I am continuously getting pop ups on the screen, cursor is not appearing, hard-disks are not accessible, internet is not working. The whole system has crashed.

Now I am trying to change it back to root but it is showing that 'directory must be owned by us 0 and have setuid bit set'. What should i do?

score 1 · Accepted Answer · edited Jun 12 '20 at 14:37

1

Simply boot in recovery mode, drop to root shell then change ownership again.

In details:

Switch on your computer.
Wait until the BIOS has finished loading, or has almost finished.
Quickly press and hold the Shift key, which will bring up the GNU GRUB menu.
Select the line which starts with "Advanced options".
Select the line ending with "(recovery mode)", probably the second line, something like:
```
 Ubuntu GNU/Linux, with Linux 3.8.0-26-generic (recovery mode)
```
Press Return and your machine will begin the boot process.
After a few moments, your workstation should display a menu with a number of options. One of the options (you may need to scroll down to the bottom of the list) will be "Drop to root shell prompt". Press Return with this option highlighted.
The root partition is mounted read-only. To mount it read/write, enter the command
```
 mount -o remount,rw /
```
Now change ownership again to root
```
 chown -R root:root /usr
```

edited Jun 12 '20 at 14:37

Community

1

answered Jun 18 '15 at 10:30

Maythux

84,289

What do u mean by press return? – Abhishek Garg Jun 18 '15 at 10:53
return is enter – Maythux Jun 18 '15 at 10:54
I have entered both the commands but the command line goes on , how to escape it? – Abhishek Garg Jun 18 '15 at 11:00
I restarted my pc after entering the commands . File ownership has been changed. But this has only partially solved the problem. The system is not hanging like before. But i unable to mount my disks . I am unable to change brightness, internet is not working, and battery percentage is not being shown. What to do? – Abhishek Garg Jun 18 '15 at 11:13
I'd suggest backing up any important files, and reinstalling. – Arronical Jun 18 '15 at 11:24
@Arronical But i m unable to mount any disk. How can i take backup? – Abhishek Garg Jun 18 '15 at 11:43

my ubuntu system crashed after changing ownership of use directory and I am unable to change back ownership to root

1 Answers1

In details: