Hi again

i m on a linux server machine log in as root. Every time i open the terminal and log in as other user i can but when ever i tried to go back under root i can not .
su -
password

the response is : su: cannot set groups: Operation failed

i have tried many commands but no success:

/etc/passwd it gave a long list i have uploaded it to u using manage attachment

/etc/group same as /etc/passwd

every time i need to access root i have to open a new terminal

i have used :
which su
Reply /bin/su
using ls -l a long list of files and directories is seen

# chmod s+u root it accept it
entering with different user and re enter with root

re have the same problem " su: cannot set groups: Operation not permitted

Thanks for ur Support
Tony

Check if for some reason /etc/ change some of the permission, due to some application or something. Normaly should be 755, but you have to see, also rest of the directories might be affected. Also check files like /etc/group /etc/passwd.

Good luck!

Forgot to add here: try "strace su - ", might give you an idea why that error is happening.