ITI-481: Unix Administration Rutgers University Internet Institute

1. ITI-481: Unix AdministrationRutgers University Internet Institute Instructor: Chris Uriarte <chrisjur@cju.com>

2. Meeting Times and Locations Per Syllabus

3. Prerequisites • Either ITI-480 Unix Fundamentals or equivalent user-level knowledge of Unix. • You MUST know how to use a UNIX text editor (i.e. pico, vi, emacs)

4. Course Overview and Goals • The purpose of this course is to teach you how to install a UNIX operating system and perform system administration activities in a hands-on environment. • The course objective will be achieved through a combination of lecture, demonstrations, and hands-on exercises.

5. Major Topics • Installing UNIX and Linux • X-Window Configuration • Installing Software • Account Management • Booting and Shutting Down • Network Configuration • Core System Services • System Monitoring and Logging • File System Administration • Configuring Specific Services: NIS, SSH, Sendmail,Telnet, FTP, Printing • Securing your Server

6. Course Resources • Textbook: To be announced • Instructor Website at http://www.cju.com/classes/ (see link to ITI 481 at bottom of page) • Workstation where each of you will install a copy of Linux. • User account on Linux server iti.rutgers.edu.

7. Today’s Agenda • Introduction to UNIX, UNIX distributions and some background concepts. • Installing Linux on your own workstation.

8. What is UNIX • UNIX is an operating system that originated at Bell Labs (NJ) in 1969. • UNIX is actually a trademark, but often used as a generic term to describe “UNIX-like” operating systems. • There are numerous different flavors of UNIX – all of which utilize similar UNIX operating system concepts, but may have different features or run on different hardware.

9. The UNIX Umbrella Hardware Vendors Linux Distributions Sun Solaris, HP HP-UX*, Compaq True 64 UNIX*, IBM AIX*, IRIX*, MAC OSX* RedHat, Mandrake†, SuSe, Debian, Caldera, Yellowdog† FreeBSD, BSDI*, NetBSD OpenBSD SCO UNIX (now Caldera/Tarantula) Other BSD Flavors * = Commercial distribution (i.e you must pay for it) † = Derivative of RedHat

10. Popularity vs. Maturity Popular Sun Solaris RedHat Linux / Linux Mandrake RedHat Linux FreeBSD / NetBSD / OpenBSD, etc. Debian Linux HP-UX Caldera Linux SuSe AIX Irix Compaq True 64 UNIX SCO UNIX Darwin (Mac OSX) Mature

11. What makes UNIX Unique? • UNIX is a multi-user, time-sharing operating system: every user gets a piece of the CPU. • UNIX flavors generally adhere to some types of standards (I.e. POSIX) • UNIX standards allow for portability of software across multiple UNIX distributions.

12. What is Linux? • A Unix-like operating system initially developed in the early 1990s by Linus Torvold. • Initially developed to run on PC hardware but has been ported to other architectures as well. • Distributed under a GNU General Public License – “free” software. • Kernel is its distinguishing feature. • Generally packaged in various distributions.

13. Linux Distributions • Vary according to included software packages, package management systems, installation process, and Window Managers. • Distributions • Red Hat Linux • Caldera OpenLInux • Linux Mandrake • Corel Linux • SuSE Linux • TurboLinux • Debian GNU/Linux • Slackware

14. Why Linux? • Linux has matured greatly over the past 5 years and has positioned itself as the most flexible UNIX distribution today. • It can be run on very low-end, generally available hardware. • Lots of software available. • Flexible – the same Linux distribution used by a hobbyist on low end hardware can be used by an enterprise on high-end hardware. • It’s the first UNIX flavor to hit retail store shelves and is easily obtainable across the world. • Administration skill sets transfer easily to and from other UNIX flavors. • It’s free!

15. Planning for Your Linux System • Is your hardware supported? • Will it be a workstation or a server? • Are there special services that you want to run (web server, email server, DNS server, etc.) • Will you need to store user and/or application data?

16. Checking Hardware Compatibility • It’s very important that you make sure you hardware is fully supported by your UNIX distribution. • Hardware Compatibility Lists (HCLs) contain the hardware supported by your OS vendor. They can be obtained at the vendor’s website. • Therefore, it’s good to know some specifics about the hardware you’re using: amount of system RAM, brand of video card, brand of NIC brand of sound card, etc.

17. Hardware Compatibility, con’t. • Some particularly good things to know about your hardware: • Video card: brand and chipset • Hard drive: total amount of hard drive space • Sound card: brand and model of sound card • Network Card: brand and model of NIC • Some vendors have searchable hardware compatibility database • RedHat: http://www.redhat.com/support/hardware/

18. Disk Partitioning • Disk Partitioning is the concept of dividing your hard disk into logical partiations, making one hard drive appear as if it’s actually multiple drives. • There’s several reasons why we partition disks: • Performance • Ease of storage management • Security

19. UNIX Disk Partitioning • In UNIX, a physical disk partition is associated with a directory path, sometimes referred to as a mount point. • All files that are in directories associated with a mount point are stored on the mount point’s physical partition. • If a directory path is not explicitly associated with a physical disk partition, its files are stored under the root ( “/” ) partition.

20. UNIX Partition Example Contains all files under the /usr directory (I.e. /usr/local/bin/pico, /usr/bin/vi, etc.) [HARD DRIVE] Example Partitioning Scheme: Total Hard Drive Space: 8GB /usr 2GB /home 4GB / (root) 1.5GB Contains all files under the /home directors (I.e. /home/chrisjur, /home/iti1234) Contains all other files and directors, such as /var, /opt, /sbin, etc. swap

21. Partition Naming • In UNIX, the system gives each partition a special device name. • In Linux, standard IDE hard drives are named /dev/hdx, where x is a unique letter given to identify the hard drive, starting with the letter a (e.g. /dev/hda) • For example, the first hard drive on the system is called /dev/hda. • Partitions are given a name with the format /dev/hdx# , where /dev/hdx is the hard drive the partition is on, and # is a uniquely assigned partition number, starting with 1 (e.g. /dev/hda1). • For example, the first partition on the first hard drive on the system is called /dev/hda1.

22. Figuring out Your Partitions • You will have to partition your disk during a typical UNIX installation. • Common partitions include: / (called ‘root’), /usr, /home, /var • Typical uses for specific UNIX partitions: • /usr – software packages • /home – user home directories • /var – log files and configuration files • /opt – software package and application installed (esp. on Solaris)

23. What do you need to Install UNIX? • At minimum, you need a CD media containing the UNIX distribution. • You may be able to set your computer to boot directly from the CD-ROM, which will start the install program. • If your computer cannot boot directly from the CD-ROM, you must create a boot floppy disk, which will boot the computer and load the installation program from CD-ROM.

24. Exercise: Installing Linux On Your Workstations • Refer to the distributed instructions.

25. Note: Linux and Other Operating Systems on a Single PC • Yes, Linux can run on a PC that is running one or more other operating systems. However, there are a number of caveats: • Linux needs to be installed after Microsoft operating systems. • You need to have unused partitions on your existing PC hard drive to install Linux. • Linux needs to be installed on one or more of its own partitions. The kernel needs to be on a primary partition. • Multi-booting is not recommended for servers. • Recommendation: If you really want to dual-boot Linux with another operating system, use a commercial software package like PartitionMagic and BootMagic (by PowerQuest)

26. Homework • Homework this week: • As noted in class • Next week: • Introduction to the X-Windows system • Software installation • Booting and Shutdown • Emergency boot procedures