ubuntu recovery mode, root shell prompt, password still required

Er... I tried the step written in
When I select "Drop to root shell prompt", it asked my root password.

As by default Ubuntu lock root user, it asked:
"Give root password for maintenance"

any other solution?

Thanks

sulogin is patched in Ubuntu, if the root account password is locked, then you are not prompted for a password in Recovery Mode.

So, you probably have enabled the root account.

To lock the root account password or set up a new password:

boot the computer

at the grub menu highlight the Recovery Mode option

press e for edit

highlight the kernel line and hit e for edit

delete ro single from the end of the line and replace it with rw init=/bin/bash

hit Enter, then b to boot

in the shell make sure that the root partition is mounted rw:

mount -o remount,rw /

lock the password (or change it):

passwd -l root

to change the password (not recommended):

passwd root

reboot the computer: press Ctrl+Alt+Del


Now you can boot in Recovery Mode and resolve the sudo problem.



make sure that the hostname is the same in both /etc/hostname and /etc/hosts


Sorry, user is not allowed to execute '/bin/bash' as root on B

edit the sudoers file:

visudo

and allow your user to use sudo. add something like:

username ALL=(ALL) ALL


username = the user name :)
ALL = from any Host/IP
(ALL) = can run as any user
ALL = all commands.


your line in the sudoers file probably looks like this:

username oldhostname=(ALL) ALL
so, you have to change it to:

username newhostname=(ALL) ALL

HowTO: Sudoers Configuration