Linux HowTo: My Top 10 Sys Admin Commands

Following is a the list of top 10 most useful system admin commands I find indispensable in managing my Linux Ubuntu Laptop.


1- Finding my ID:
        # id -a                                        - shows who I am, what groups I belong

2- What machine:
        # uname -a                                 - shows my OS version, kernel, Platform

3- OS Version (specific to Ubuntu):
        # lsb_release -a                          - shows my Ubuntu version and release

4- Hostname:
        # hostname                                 - shows me the hostname, allows to set new hostname also.

5- Run level:
        # who -r                                     - shows current and previous runlevel, default is 2 on Ubuntu

6- Initialization state:
        # init <n>                                    - sets the initialization state, n=0 is halt, n=6 is reboot, n=2 is default.
7- Date and Time:
        # date                                         - show system date and time. Also allows to set new date/time as root


8- Network Interfaces:     
        # ifconfig -a                                - shows all my network interfaces and status thereof

9- Network connectivity:
        # ping   <hostname>                   - polls a remote node and verifies network connectivity using ICMP

10- Network connectivity:
        # traceroute <hostname>            - Traces each hop in the path of a network packet