Comment 14 for bug 523896

I had the same situation on my ubuntu 9.10 Karmic , I was trying to add my user id to dba Group in order to star
and stop the DB services by own ,
raja@ubuntu:~$ usermod -a -G dba raja
usermod: cannot lock /etc/passwd; try again later.
i checked for any process locked the /etc/passwd file but found nothing .
Then i tried to run the command with sudo
this time it worked.