Felitaur Enterprises, Linux Sysadmin, Week 2

Overview
Review of Basic UNIX commands, some additional Configuration You should be familiar with the basic UNIX commands You should also be familiar with the general layout of the filesystem Understanding of the various "run levels" for the booting process The following commands/programs will be used/discussed this week: Ctrl-alt-F1 to Ctrl-alt-F6 (virtual terminals) ctrl-alt-F7 (gets you back to the GUI) ps Basic commands- cd, ls, less, more, rm, mv, cp, mkdir Locating files- which, locate (run updatedb), find Editing files- vi and pico Piping and redirection- > >> \| Job Control- ps, jobs, kill, fg, bg, & and ^z Permissions- chmod, chgrp, rwx, groups and /etc/passwd, /etc/group and /etc/shadow Run Levels and the Run Level Editor /etc (xinetd.d, inittab, fstab, services) /etc/rc.d and /etc/rc.d/init.d /etc (shadow, passwd, resolv.conf, hosts) /proc The File System / & /etc /usr /bin /dev /var /sbin /home /mnt /lib /proc /tmp /boot Booting init
Questions
What is /dev/null ? Where would you find system programs? What would be horribly wrong about doing the following as root: cd /usr/bin ls -l > less What directory are the init scripts (for starting and stopping services) kept? Why is it dangerous to run as root? What is the difference between the various run levels? (1-6)? What run level do we normally boot into? What run level does "linux single" put us into if typed at the "boot:" prompt? Where are the encrypted passwords kept? Where are log files kept? **What directory in /etc contains some of the internet services that are running at boot (such as imapd, pop3)? How do you restart this service? What is so special about the /proc directory? What is kept there?
Activities & Assignments
Get your FTP server (vsftpd) up and running and put a file in /var/ftp/pub Services to Shutdown
Resources
Xinetd