RHEL : A better cheat Sheet

contents –

:Know your machine 💻

:Monitering

:Tweaks for better Administration

:Networking

:Searching

:Web Console

————————————————-
Bonus Command –

Record Terminal session –

script script_name.txt – to start record session
exit – to stop session
cat script_name.txt – to view the recorded session

1. Know your machine

Display Linux system information-

uname -a

Show operating version & name-

cat /etc/os-release

Show host name-

hostname
hostname -I

Display CPU information-

cat /proc/cpuinfo

Display memory/RAM –

cat /proc/meminfo

Display RAM usage (

free -h – Human redable format
free -m – in MBs
free -g – in GBs

Displays all environment variables running on the system.

env

reboot History

last reboot

Monitering

NMON – ‘TOP’ alternative for monitering-

nmon
NMON can be used as a better ‘top’ alternative.

1.CPU utilization,
2.Memory
3.Disks
4.Network utilization & more
In a better viewe where refresh rate can be adjusted by pressing +, – buttons.
Stats can be saved to CSV for later analysis & graphing.

Networking

Check connectivity & port opening status

ssh -vvv <IP> -p <PORT>
ssh -vvv 192.168.186.42 -p 9090

connection succesful –

connection failure –

Purpose of machine

TWEAKS –

Increase SSH timeout –

vi /etc/ssh/sshd_config
insert/assign values as per following to set timeout to 1 hour –

ClientAliveInterval 1200
ClientAliveCountMax 3

RHEL Web Console

A web-based interface can be used for managing and monitoring RHEL systems in realtime. Follow the commands to enable & use RHEL web console-

Enable web console –
systemctl enable –now cockpit.socket

if cockpit package not installed –
dnfinstall cockpit

open port 9090 for web console –
firewall-cmd –add-service=cockpit –permanent

open browser & type URL –
https://IP or hostname:9090
e.g. https://192.168.186.42:9090/system

Networking

vim

Please follow and like us: