CyberSecurity Linux Command

This is the fifth week of Beginners Linux Commands. This week, I will share 12 commands that you can use to see Performance monitoring and statistics of the Linux system.

1. top = Display and manage the top processes

2) htop = Interactive process viewer (top alternative)

3) mpstat 1 = Display processor related statistics

4) vmstat 1 = Display virtual memory statistics

5) iostat 1 = Display I/O statistics

6) tail 100 /var/log/messages = Display the last 100 syslog messages (Use/var/log/syslog for Debian based systems.)

7) tcpdump -i eth0 = Capture and display all packets on interface eth0

8) tcpdump -i eth0 ‘port 80’ = Monitor all traffic on port 80 (HTTP)

9) lsof = List all open files on the system

10) lsof -u user = List files opened by user

11) free -h = Display free and used memory ( -h for human readable, -m for MB, -g for GB.)

12) watch df -h = Execute “df -h”, showing periodic updates