CompTIA Linux+ (XK0-006)Services and User ManagementMedium
A system administrator wants to limit the number of concurrent login sessions for a specific user, `devuser`, to a maximum of 3. Which configuration file should be modified to achieve this?
- A/etc/security/limits.conf
- B/etc/profile
- C/etc/pam.d/login
- D/etc/login.defs
Show answer & explanationAnswer & explanation
Correct answer: A. /etc/security/limits.conf
The `/etc/security/limits.conf` file is used by the Pluggable Authentication Modules (PAM) `pam_limits.so` module to set resource limits for users, including the maximum number of concurrent login sessions.
Why the other options are wrong
- B. This file is a system-wide initialization script for shell environments and doesn't manage login session limits.
- C. This file configures PAM for the login service but doesn't directly set session limits; it would call `pam_limits.so` which uses `limits.conf`.
- D. This file defines system-wide defaults for new users and password policies, not concurrent session limits.
pam_limits.so and limits.conf
The `pam_limits.so` PAM module uses the `/etc/security/limits.conf` file to enforce resource limits for users, such as CPU time, memory, or maximum concurrent login sessions.
- Controls system resource usage for users.
- Configured via `/etc/security/limits.conf`.
- Part of Pluggable Authentication Modules (PAM).
Memory trick: PAM sets LIMITS on your resources.