How to change root password in ubuntu?

I am trying to change root password in my Ubuntu system.

This is what I did:

ashot@ashot-desktop:~$ sudo passwd root 
passwd: Authentication token manipulation error 
passwd: password unchanged

How do I change root password in Ubuntu?

Solution 1:

Usually there is no need to set a root password. See: https://help.ubuntu.com/community/RootSudo

To set or change your (root) password:

sudo -i
passwd

To lock it again

sudo passwd -dl root

Solution 2:

When you use sudo your already accessing root you don't have to specify root.

sudo passwd

If your trying to do this from recovery root you should:

mount -rw -o remount / 
passwd

Solution 3:

If 'ashot' is your root account, don't call 'sudo passwd'. I've been doing that for the past few months and it wouldn't change my password.

To change my password, I had to call 'passwd' without 'sudo'. Otherwise, the password modification is not taken account of.