Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

i cant login as super user using su command ,previously it was successful and i am sure that password is correct,previosly there was an issue by changing file permission of www folder and i follow this link to correct it http://sysadminnotebook.blogspot.in/2012/06/how-to-reset-folder-permissions-to.html after that i cant login as su

share|improve this question

2 Answers 2

If I am right, you can not login directly as root with su in Ubuntu. You need to run the command with the prefix sudo, or in your case obtain a shell with sudo su.

share|improve this answer
    
no,it is not the case,it was previously able to use su, the out put of sudo su is "sudo: must be setuid root" –  sajith May 8 '13 at 6:45
    
The /usr/bin/sudo must be setuid normally, and to do that you can run chmod 4755 /usr/bin/sudo. But since you need root access to execute this command, you are trapped. One way I see to solve this is to boot from a live cd, mount the root partition, execute this command to setuid sudo and reboot the system. –  StreakyCobra May 8 '13 at 7:07
    
i have one terminal with root access opened before this operation,so i think i can do that –  sajith May 8 '13 at 7:09

You should boot into live mode, and then mount the drives and then change the permission for the file /usr/bin/sudo

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.