Master Real-Time Log Monitoring on Linux with tail, multitail, lnav & less

1. tail Command – Monitor Logs in Real Time

The tail utility is the most common way to watch a growing log file. Use the -f flag to follow a file: $ sudo tail -f /var/log/apache2/access.log The built‑in tailf command behaves the same way without needing -f: $ sudo tailf /var/log/apache2/access.log When logs are rotated, use -F so tail follows the new file descriptor: $ sudo tail -F /var/log/apache2/access.log To display only the last two lines while following, combine -n and -f:

$ sudo tail -n2 -f /var/log/apache2/access.log

2. Multitail Command – Watch Multiple Logs Simultaneously

Multitail can monitor several log files at once and lets you scroll back within each stream.

Installation:

$ sudo apt install multitail   # Debian/Ubuntu
$ sudo yum install multitail   # RedHat/CentOS
$ sudo dnf install multitail   # Fedora 22+

Example – display both access and error logs together:

$ sudo multitail /var/log/apache2/access.log /var/log/apache2/error.log

3. lnav Command – Another Multi‑Log Viewer

lnav offers similar multi‑file monitoring with a richer interactive interface.

Installation:

$ sudo apt install lnav   # Debian/Ubuntu
$ sudo yum install lnav   # RedHat/CentOS
$ sudo dnf install lnav   # Fedora 22+

Run lnav on two logs:

$ sudo lnav /var/log/apache2/access.log /var/log/apache2/error.log

4. less Command – Real‑Time View with Shift+F

The classic pager less can also follow a file. Press Shift+F after opening, or start it with +F: $ sudo less +F /var/log/apache2/access.log Like tail, less will keep displaying new lines as the file grows.