Felitaur Enterprises, Linux Sysadmin, Week 1

Overview
After working as a simple user on a linux system for 4-5 weeks, we now can start the first week of being a system administrator on a linux distribution. NOTE!! At this point you should be VERY familiar with the following commands/concepts, as they will be necessary for the rest of this class, and it will slow down the class significantly if we have to go over these again and again. PLEASE PRACTICE THE FOLLOWING if you are not 100% comfortable with them. vi and pico (You should know the basic commands and how to use these editors as second nature. VERY crucial). cd If I say "go to the etc directory" you should know to type cd /etc permissions via chmod less and more grep and ps and piping them to less or more If any of the above is difficult for you, go back to the appropiate topic pages and practice these until you are able to use them like second nature. Goals: Installation of Linux to Removable Hard Drive (see Linux System Administration for appropriate links. Go over the history of UNIX, Linux and the GNU and it's GPL (GNU Public License) Installation Issues kickstart Hardware Support "Dangerous" commands Files used during bootup Runlevels and how to configure them Some configuration of your system Learn where help files are located in Linux The following programs/files/directories will be discussed for this topic: : .bash_profile (in your user account home directory su lets you switch users, by default to the root user if you know the root password /etc/inittab (controls which run level you use by default) /etc/fstab (controls what drives/etc. are mounted during bootup) /etc/rc.d/ (contains the init.d and rc#.d directories) /etc/rc.d/init.d/ (Directory that contains the start/stop scripts for the entire system) /etc/rc.d/rc#.d (rc0.d-rc1.d...rc3.d...rc6.d, contain symbolic links that point to the scripts in /etc/rc.d/init.d, if you see a S85httpd you know that the httpd server (apache) is started in this runlevel, and if you see a K15portmap, you know that portmap is killed in this level) chkconfig --level 3 servicename on/off service servicename start/stop/restart/status GUI tool to edit runlevels(redhat, system utilities, server settings, services) init shutdown -h now (vs -h\r)
Questions
What is GNU? What does it have to do with UNIX and Linux? What is open source software? What big internet company put one of their most popular software packages into the open source hat? Why are winmodems a bad idea, even for windows? What do the run levels represent? Where is the default run level set? Why is it dangerous to run as root? What is "dangerous" about the following commands? rm chmod chown chgrp fdisk Why is the on/off switch just as potentially deadly to a UNIX/Linux system? How do you turn off a service? How do you make sure that service is not turned back on if you reboot? Why do you need to edit the path in your .bash_profile file? What are some of the Hardware Issues with installing UNIX/Linux?
Activities & Assignments
Open the .bash_profile file in your home directory (as a user, not root) and change the line: PATH=$PATH:$HOME/bin: TO: PATH=$PATH:$HOME/bin:/sbin:/usr/sbin This will allow you to use commands like chkconfig and service and shutdown without having to type /sbin/ in front of them. Use chkconfig to get rid of unwanted Services Using the file manager Learn how to "hunt" down information on Linux/Unix locate (need to run updatedb) find info man pages /usr/doc installed html pages (locate html \| less) How-to's Linux Documentation Project Use of search engines such as www.google.com News groups at groups.google.com comp.os.linux.* comp.os.linux.security Use of main website provided by your distributor, in this case www.redhat.com
Resources
Linux Documentation Project Linux Hardware Compatibility HOWTO Red Hat Hardware Compatibility List SCSI HOWTO Tom's Hardware Guide