Linux Console Information
- @for Linuxers
- @author Kai Ruhl
- @since 2010-09
Ok, so you are on a Linux system. On the console.
And you want to know whats going on. This tutorial is for you!
We will cover the following topics:
- Users and Load
Without further ado, here we go...
Be root (whoami and sudo su) and type the following:
- uname -r: What kernel you are running.
- lspci: What hardware is connected to your PCI bus.
- lsusb: What hardware is connected to your USB bus.
- cat /proc/cpuinfo: Number and properties of your CPUs.
- cat /proc/meminfo: What happens to your RAM.
- hdparm -I /dev/sda: The state of your hard drive.
- df -h: Mounted partitions, and their sizes.
- du -sh <directory>: The size of a directory and all of its files.
Users and Load
Now you got the system running. Who is running on it, anyway?
Try the following (again as root):
- ps ax: All running processes, in a nutshell.
- top (or better, htop when available): All running processes, including the owning users. Also good with the -u <username> option.
- vmstat: One-line summary of system resources. Also good as vmstat 1 (gives update every second).
- w: What users are online, and what are they doing? Also as w <username>.
- uptime: How long has the system been running since last reboot?
- iostat: Activity on your harddisks/partitions right now.
See also this this useful
for additional command line options.
We got the machine, now we get to the wires or radio waves attached to it.
- netstat -l: All open server ports, including stuff running over local ports.
- ss: Established connections to other computers (and to localhost).
- iptraf: The htop of network packages.
- tcpdump -i eth0 'tcp port 22': Sniff e.g. SSH traffic on a network card.
- nmap <hostname>: What ports your other machines have open.
So, this was our little tour de force! A little more:
I hope you are now a little bit smarter about your Linux system.
Any questions or comments, contact me via mail to kain at the above domain.
Thanks for leaving a part of your attention span here, and have a good day!