Logon failure after Linux root password reset

Cause

The i (Immutable) attribute is set on the /etc/passwd or /etc/shadow file, which prevents the new password from taking effect.

Solution

1. Connect to the Linux ECS instance as the root user. See Use Workbench to connect to a Linux instance over SSH.

   Important

   Use the original valid password to connect. If the original password is also invalid, connect to the instance by using VNC.

2. Run the following commands to check file attributes:

   # Check the attribute status of the passwd file.
   lsattr /etc/passwd
   # Check the attribute status of the shadow file.
   lsattr /etc/shadow

   • If no special flag such as i or a appears, the attributes are normal.

   • Sample abnormal status:

     [root@iZbp1b0xxx ~]# lsattr /etc/passwd
     ----i------------ /etc/passwd

     The i flag indicates that the /etc/passwd file has the immutable attribute.

3. If abnormal attributes exist, run the following commands to remove them:

   # Remove the immutable attribute from the passwd file
   chattr -i /etc/passwd
   # Remove the append only attribute from the shadow file
   chattr -a /etc/shadow

4. Recheck file attributes:

   lsattr /etc/passwd /etc/shadow

   The output should not contain the i or a flag.

5. Reset the root password in the ECS console. See Reset the logon password of an instance.

6. Log on with the new root password. If the connection succeeds, the issue is resolved.

Appendix