Users can't login to the system include root

Issue

• In /var/log/secure, it shows the below

$ cat /var/log/syslogs/authlog
2013-12-20T00:33:26.843226+00:00 localhost pam_afs: AFS Ignoring superuser root
2013-12-20T00:33:57.125930+00:00 localhost pam_afs: AFS Ignoring superuser root
2013-12-21T07:46:18.763754+00:00 localhost pam_afs[8244]: AFS Won't use illegal password for user r
2013-12-21T07:46:18.763772+00:00 localhost login[8244]: FAILED LOGIN SESSION FROM (null) FOR r, Authentication token is no longer valid; new one required
...
2013-12-21T12:05:42.923703+00:00 localhost pam_afs: AFS Ignoring superuser root
2013-12-21T17:19:23.810538+00:00 localhost pam_afs: AFS Authentication failed for user mysql. user doesn't exist
2013-12-21T17:19:25.918978+00:00 localhost pam_afs: AFS Password required but not supplied by user mysql