In the test environment, many operations require root user rights, in order to improve the efficiency of testing, so sometimes want to directly use the root user login system, but the CentOS graphical interface by default does not allow the root user login, this is due to Pam restrictions, the following settings are required:
1, backup, any operation of the system needs to be backed up CD/ETC/PAM.D/CP GDM gdm.bak2, modify vim GDM Delete or add # Comment line at the beginning of the row: Auth required pam_succeed_if.so user! = root Quiet Log off the user re-login with another user, enter the root username and password. The above command in the CentOS6.2 64-bit test through PS: the formal production environment or the recommended use of normal user login, require advanced permissions to switch to the root user
The CentOS 6.2 graphical interface allows the root user to log in