Today i clone a redhat vm, But don't remember the password. ok, reboot, enter into the single user mode. How to enter into single user mode?
1.Edit the kernal when booting, append a "1" in the end. press enter to save. finally press "b" boot it
2.But when i try to change the password, it has this error. "Authentication token manipulation error"
Try to directly delete the passwd, success.
#passwd -d root
3.reboot , login normal mode. try to reset root password, The issue also exist.
4.check the passwd and shadow file.
#cp /etc/shadow /etc/shadow.back
#pwconv : This command generate a new shadow file by passwd file.
5.reset root password is ok.
# passwd root
Changing password for user root.
New password:
BAD PASSWORD: it is based on a dictionary word
BAD PASSWORD: is too simple
Retype new password:
passwd: all authentication tokens updated successfully.