su: Authentication failure problem solution

       If you receive a "su: Authentication failure" error message when sutrying to switch to rootthe user using the command, there are several possible causes:

1. Password error: The password you entered rootfor the user is incorrect.

2. rootUser account disabled: The system administrator may have disabled rootthe user account, or made its password unavailable.

3. suCommand disabled: The system administrator may have disabled suthe command, or restricted which users can use suthe command.

The way to solve this problem:

1. Confirm rootUser is Enabled: Check rootif the user is disabled. If rootthe user has been disabled, you will need to contact your system administrator for assistance.

2. Confirm suthat the command is available: Check to see suif the command has been disabled, or restricted which users can use the command. If this is the case, you will need to contact your system administrator for assistance.

3. Enter sudo passwd root to reset the password, and enter the new password to log in after reset.