What is PAM and what are the most important tasks I should have memorized to pass the PAM portions of a task-based exam such as the LFCS exam (assume that I am taking a RHEL-based exam)?

PAM stands for Pluggable Authentication Modules. It is a system that allows for flexible authentication and authorization management in Linux systems. PAM enables administrators to configure multiple authentication methods for various applications and services, and to specify which methods should be used in which circumstances.

To pass the PAM portions of a task-based exam such as the LFCS exam, you should have memorized the following tasks:

  1. Understanding the basic PAM configuration files and their purpose: PAM configuration files are located in the /etc/pam.d/ directory. You should be familiar with the different configuration files and their purposes, such as system-auth, password-auth, login, sshd, and su.

  2. Adding and configuring authentication modules: You should know how to add and configure authentication modules for different services and applications. Some commonly used authentication modules include pam_unix, pam_ldap, pam_krb5, and pam_winbind.

  3. Configuring authentication policies: You should know how to configure authentication policies using PAM. For example, you can specify the minimum

  4. length and complexity of passwords, the maximum number of failed login attempts before locking out an account, and the maximum time allowed between password changes.

  5. Understanding PAM control flags: You should know the different PAM control flags, which determine how PAM handles the outcome of a module. The most common control flags are required, requisite, sufficient, and optional.

  6. Troubleshooting PAM issues: You should be familiar with troubleshooting common PAM issues, such as login failures, authentication errors, and permission issues.

By mastering these tasks, you should be able to pass the PAM portions of a task-based exam such as the LFCS exam.


Kwame is a RHEL system administrator at NASA. He wants to use PAM to set a default minimum 10 character password for all new users on his RHEL system. How will he do it?

To set a default minimum 10 character password for all new users on a RHEL system using PAM, Kwame can follow these steps:

  1. Open the /etc/pam.d/system-auth file in a text editor with root privileges.

  2. Add the following line to the end of the file:password    requisite minlen=10

  3. This line specifies that the module should be used for password authentication and sets the minimum password length to 10 characters.

  4. Save the changes to the file and exit the text editor.

By adding the module to the system-auth PAM configuration file and setting the minlen option to 10, Kwame has successfully set a default minimum 10 character password policy for all new users on the RHEL system.

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