System : Red Hat Enterprise Linux Server release 5 (Tikanga), Version : 2.6.18-8.el5xen
Problem : today ,we can not login in by root or other users(here we make sure our name and password is correct). but it seems that the system’s username and usepassword system have be corrupted by something yestoday.
Method : go in to single mode Linux ,and change the root the other users’ password .
press "e" when system booting ,to go to Grbu edit .
the display like this :
module /boot/vmlinuz-2.4.21-15 EL ro root=LABEL=/
select the module line ,then press "e" to edit that line.
add a "single" before the "ro" ,like this :
module /boot/vmlinuz-2.4.21-15 EL single ro root=LABEL=/
then press "Enter" to enable this change .
then press "b" to reboot.
system reboot ,go into a shell like :
then you can do :
sh-2.05# passwd root
to change the password of root .