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OPS235 Lab 1 GNU/Linux Installation - Fedora 16
Introduction
In this lab, you are going to install the Fedora (GNU/Linux Distribution) to your hard disk from DVD.
Although this will be a simple install, you will be required to perform other Fedora installations using Virtual Machines. This main install will be very important, since you need to properly install Fedora in order to run other virtual machines to install other Fedora disributions.
After the installation, you will collect baseline information about your Fedora GNU/Linux system, do some post installation configuration to prepare your system for the remainder of the labs.
Objectives
- To perform a GNU/Linux installation using the Fedora 16 distribution
- To obtain network configuration from a DHCP server
- To investigate information during and after the Fedora 16 installation
Required Materials (Bring to All Labs)
- Fedora 16 LIVE CD - You can burn this onto a CD-R in the Open Lab
- Fedora 16 x_64 Installation DVD - You can burn this onto a DVD-R in the Open Lab
- SATA Hard Disk (in removable disk tray)
- USB Memory Stick (minimum 64M)
- Lab Logbook (to make notes and observations).
Prerequisites
- None (First Lab)
Linux Command Online Reference
Each Link below displays online manpages for each command (via http://linuxmanpages.com):
Resources on the web
Additional links to tutorials and HOWTOs:
Performing Lab 1
Investigation 1 - performing Fedora DVD Install on Hard Drive
- Insert your removable SATA hard disk in the drive tray.
- Set your computer's drive selector switch to external (also labelled #4) since we will be installing from DVD.
- Power up the computer and insert the Fedora 16 Installation DVD into the CD/DVD drive.
- Wait until the Fedora DVD boots (could take a few moments).
If for some reason, the Fedora16 Installation DVD does not boot:
- Restart the computer, and press the function key F10 to specify the device to boot (eg. DVD drive).
- If the user is prompted for a password, simply press ENTER (without typing any password) at the password prompt.
- You will need to perform this technique to ensure that Fedora boots from the hard drive (in future labs).
- If you have tried this technique, and the Fedora Installation DVD does not boot, you may have to reburn another Fedora Installation DVD.
- Note the time at the beginning of your installation.
- When the Fedora16 Installation DVD boots, it will prompt the user to test the media (i.e. DVD) for integrity. Since time is limited for installation in the lab, select SKIP. On the other hand, if the install did not work, then you can test out the integrity of the DVD in the computer lab during your spare time.
- Select the default language (English) in the next install screen, and click Next.
- Select the default keyboard layout and Basic Storage Devices in the following installation screens.
- Set your hostname (name of the computer) to - f16host (one word, no space, all lowercase). Record in your lab logbook why you think it is important to set your hostname to this exact name instead of using another name...
- Set your time zone to Toronto.
- Root Password: enter a password of your own choosing. Pick one that is really, really hard to guess to protect your system. (Recommendation: use the first letter and all the punctuation from a favorite phrase or song verse. For example, "To be or not to be, that is the question!" could become the password "Tbontb,titq!").
- Select Use All Space, to have the entire disk for the current Fedora16 OS.
If are using an existing removable Hard Disk from a previous course, you must allow the Installation DVD to "wipe" all previous contents prior to proceeding with this lab (no exceptions).
You may be "hestitant" to want to use the entire disk for just one operating system, but we will be using software that will allow us to run virtual machines for installation of other versions of Fedora and allow them to run at the same time as our main (host) Fedora distribution.
- When prompted, make certain to select Fresh Install in order to erase any previous contents of the hard disk.
- You will be prompted to confirm the options that you have chosen prior to performing the DVD install. If you are not certain, you can "Go Back". As soon as you are satisfied with your selections, then click "Write Changes to Disk.
- Record briefly in your lab logbook what activity occurs during this installation process.
- Select in the next screen the Graphical Desktop applications, and in the additional repositories section (at the bottom) make certain to select the default for the additional repository items. "Fedora 16 -x86_64 - Updates", then proceed.
- Add in your lab logbook a brief description of the term "software repository" and what its major purpose serves (what you think it does). We will not add any existing repositories since we are not currently connected to the Internet. Therefore, we will customize the repositories later.
- Proceed with the installation. This may take some time. Record in your lab log-book the general steps in the installation process (displayed in the dialog box).
- When installation is complete, a screen will confirm completion, and ask the user to remove the DVD, and reboot the computer. Write in your lab log-book the time it took to perform this DVD Fedora install.
- Remove the Fedora Installation DVD, and click Reboot.
Each time you boot from your removable hard drives:
- Press the function key F10 and specify the hard disk device to boot (eg. SATA drive).
- If the user is prompted for a password, simply press ENTER (without typing any password) at the password prompt.
- When the system starts, set or accept the time and date default.
- Create a user account for yourself using the same name as your learn account, and create a suitable password (do not forget password!).
- Normally, you would want to enable Network Time Protocol, but since we will be experimenting with the networking turned off in later labs, leave it disabled.
- Click on Do Not Send Hardware Profile.
- Finish the post-installation customization, wait for the login screen to appear, and then login to your Learn account.
- Proceed to Investigation 2</il>
Investigation 2: How many files packages and files are installed on the system?
For the rest of the tasks in this lab, you must login to your system using your Learn account and execute all commands under your learn account. If you get a Permission Denied message when trying to execute a command, then switch to the superuser account by running the command su - and type in the password for "root". Once the intended command is executed, type "exit" to exit from the superuser account and return to your regular Learn account.
Throughout this course, you may need to execute commands using the privileges of the the administrative user (username "root", also called the "superuser"). To switch from your account to the root account, type the command:
su
After switching user notice and make note of the change in your shell prompt. Also note the difference in output for the whoami andpwd commands.
Whenever this is required, make a note of it, and determine why superuser privilege is required.
When you are finished using the root account type exit to return to your previous account. Avoid using the superuser account unless absolutely necessary, because the superuser account has unlimited privilege and a typo can destroy your system.
In some documentation, you may see the command su - used in place of su. The dash argument causes su to go through the steps that would normally be performed when the root user logs in, including (1) running the startup scripts (such as/etc/profile and /root/.bash_profile and (2) changing to the root user's home directory (/root).
Note that the root user's home directory (/root) is not the same as the root directory of the system (/). It is also in a different directory than the rest of the home directories, which are typically in /home -- the reason for this is that /homeis sometimes on a network filesystem shared by another server (as is the case on Matrix), and it's important that the system administrator be able to log in to the system even if the network is not operating normally.
Record the commands used and the output generated in each of the following steps:
- To find all the mount points, enter the command:
mount- Study the output and record all the mount points in your log book.
- The name of the installation log file is
/root/install.log-- It is an ASCII file (how can you be sure?) and can be viewed with thelesscommand. - You can make use of this file to determine how many packages have been installed: complete the following command to count the number of packages listed in the installation log file:
-
grep ________________ /root/install.log | wc -l
-
- Using the
rpmcommand: you can also use the following commands to list all the installed packages, and the total number of packages installed:-
rpm -q -a -
rpm -q -a | wc -l -
rpm -qa | wc -l
-
- The
-qoption means query, and the-aoption means all (in other words, query all installed software packages). Did you get the same number of packages from the above two methods? - Some of the files on your system were installed with the software packages, and some were created by system activity (for example, by creating your Learn account and by logging in). If you know the package name (from the
install.log), you can list all the files that were installed from the package by using the following command:-
rpm -q -l package_name
-
- This combines the
-q(query) option with the-l(list filenames) option. - You can pipe the outupt through
wc -lto count the number of lines:-
rpm -ql package_name| wc -l
-
- Using what you learned in steps 3, 4, and 8, get a count of the total number of files installed by all of the software packages on your system.
- To find out the name that you have assigned to your Linux system, enter the command:
hostname - To find out the kernel version of your GNU/Linux workstation and the date it was created, enter the command:
uname -r - To find out all the system processes running on your GNU/Linux workstation, enter the command:
ps -ef - To capture the list of all the system processes to a file called
ps.lst, enter the command:ps -ef > ps.lst - Copy the installation log file
/root/install.logand the file ps.lst to a USB memory key, or scp to your matrix account as a backup.
The Fedora 16 software is updated frequently to add features, fix bugs, and upgrade security. Perform a system update to get the latest versions of the packages installed in Fedora: Start the Firefox web browser, turn off popup window blocking (select Edit>Preferences, then select the Content tab and uncheck the box to Block Popups), then login to SeneNET. Open a terminal and type
su to start a shell as root. Enter the command yum update This will download and install all of the packages that have been updated since the installation DVD image was created. If you complete this command at Seneca it should run quite fast as Seneca College hosts a Fedora Repository mirror (a copy of all of the current fedora packages, on a local web server).Investigation 4: What is a runlevel?
After the kernel boots, it starts a single program, called init. A running instance of a program is called a process -- the init process always has a process ID (PID) of 1. All other processes on the system are started by init, or they are started by processes started by init.
Most current Linux systems use some variation of the init system originally developed for Unix System V (called "sysvinit") or a newer version called "upstart".
These systems employ the concept of "runlevels" -- groups of software that can be selected, so that the system can be run in various modes. In Fedora systems, these runlevels are used:
| Runlevel | Description |
|---|---|
| 0 | Halt (powers off the system) |
| 1 | Single-user maintenance mode, network not running, character-mode display |
| 2 | Not normally used - originally meant: Multi-user mode, network not running, character-mode display |
| 3 | Multi-user mode, network running, character-mode display |
| 4 | Not normally used |
| 5 | Multi-user mode, network running, graphical user interface |
| 6 | Reboot |
Various Linux distributions may use the runlevel numbers differently. For example, on some Debian/Ubuntu systems, the default (standard) runlevel is 2.
In order to implement runlevels, init uses a configuration file and a number of script files:
-
/etc/inittabis the configuration file, which sets the default runlevel. -
/etc/rc.d/init.dis a directory of scripts.
In order to determine which of the startup scripts should be executed in each runlevel, the one directory per runlevel is created (/etc/rc.d/rcX.d, where X is the runlevel). This directory is filled with symbolic links to the startup scripts in /etc/rc.d/init.d
- To find out the value of the runlevel your GNU/Linux system goes into after boot, enter the command:
grep initdefault /etc/inittab - You should get a single line containing ":" as the field delimiter. The second field stores the value of the runlevel the init process will use after a reboot. Record the output in your log book.
- A list of processes that should be running at a given runlevel can be found in the directory
/etc/rc.d/rcX.dwhere X is the runlevel. Do a directory listing of that directory and study what files are in there. Pay attention to the first three characters of each file name. They have special meaning to the system. Record your observation in your log book. - Make a backup of the file /etc/inittab with the command:
cp /etc/inittab /etc/inittab.original - Edit the file
/etc/inittaband change the default runlevel to 3. Save the change and reboot your system. - After the reboot, you should get a "Text Login Screen". Login with your Learn account and type startx at the command prompt. Describe what happens in your log book.
- Enter the command:
runlevel-- this shows the previous and current runlevel. Record the values in your book.
Answer the Investigation 4 questions in your lab log book.
Investigation 5: What is the network configuration?
- To check the network configuration settings obtained from the DHCP server, run the following commands, describing the output in your log book:
- ifconfig
- route
- netstat -rn
- nslookup (at the > prompt, enter the word "server" (do not type the quotes) and record the output. Type exit to leave nslookup).
- Find the following information in the output of the above commands:
- MAC address (physical or hardware address) of the ethernet network interface
- The IP address (logical address) assigned by the DHCP server
- The default route (gateway)
- The DNS nameserver
Answer the Investigation 5 questions in your lab log book.
Investigation 6: How do You Secure the Grub Boot Loader?
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Before proceeding, use the
mount command to check to see which filesystem is mounted on the mount point /boot. If it is /dev/sda5, it is the wrong filesystem. This may be caused by a duplication of serial numbers which is the result of Lab 1; you can fix this problem with this series of commands:
mkdir /media/sda5 /tmp/sda5-files umount /dev/sda5 mount /dev/sda5 /media/sda5 cp -v -R /media/sda5/* /tmp/sda5-files umount /dev/sda5 mkfs -t ext3 /dev/sda5 mount /dev/sda5 /media/sda5 cp -v -R /tmp/sda5-files/* /media/sda5 rm -rf /tmp/sda5-files mount -a
By default, the Grub boot loader allows anyone with access to the computer at boot time to set the runlevel, or change the boot parameters, which can allow them to influence the init process and which kernel image is loaded. Anyone with access to the boot prompt can therefore bypass security controls and control which software is loaded. For example, rebooting to runlevel 1, known as single user mode, gives the user root priveleges without the need for a password! Obviously, giving a non-administrator this much control can be dangerous, and it is wise to protect the boot loader with a secure password.
We will need to choose a password, encrypt with the grub programs hash utility (called md5crypt), and add the encrypted hash of your password to the grub configuration file, /etc/grub.conf
If you lose the GRUB password you will not be able to change boot parameters when you boot the system. If you need to write it down, put it in a safe place, where no one will be able to tell what it is for.
- Choose a suitable password.
- Open the grub program by typing the command:
grub - At the grub prompt, type in the command:
md5crypt - When prompted for a password, carefully type in your password. The program will display the encrypted hash of your password. Carefully write down that encrypted hash generated by the program.
- Type the command:
quitto exit the grub program. - Open the grub configuration file,
/etc/grub.conffor editing. (This file is actually linked to /boot/grub/grub.conf). - Carefully add the line:
password --md5 password-hash(note: password-hash is the hash you generated with md5crypt) Place this line between the splashimage line and the title line. If there are other lines there, there is no need to remove them. Just insert your password line as a new line. - Make sure you have not made a mistake. What you type in must match exactly the output from the md5crypt command.
- While you are editing the file you should also increase the timeout for grub to automatically boot the default OS. Edit the line
timeout=0totimeout=5to give us more time to interrupt the process. - You should also ensure that the grub boot menu is not hidden. Add a hash sign (
#) to the start of the line which reads:hiddenmenu - Save the file and exit. Your Grub boot loader is now password protected.
- Find the section of this article that explains how to change the runlevel at boot time, and read it. Reboot your system, trying to change to runlevel 1 from the boot prompt, and see if the password protection worked.
- From now on, when you want to change boot parameters when you boot, you must type lowercase
pat the boot prompt and enter the required password.
Completing the Lab
Check off the following items before asking your instructor to check your lab:
- Task 1 - Created correct partitions in /dev/sda
- Task 2 - Install GNU/Linux Workstation using Fedora
- Task 3 - Collect system information after installation.
- Task 4 - Customize and configure boot time environment
- Task 5 - Collect network information
- Task 6 - Password protect Grub Bootloader
Arrange evidence for each of these items on your screen, then ask your instructor to review them and sign off on the lab's completion:
- Issue command fdisk /dev/sda, and use p command to display partitions
- Grub is password protected.
- Can login with your "learn" account name
- Has all the mount points
- Has the package count
- Has edited the default runlevel
- Has the correct IP address and MAC address
- Find out the default route (gateway)
- IP of the DNS name server
- Name and contact information on your disk pack
Feel free to change your default runlevel to 3 or 5 according to your own personal preference. Note that later labs may assume a particular runlevel.
Preparing for the Quizzes
- How many packages were installed?
- How many files (correct to the nearest hundred) were installed?
- How many mount points were used?
- How many users were created automatically on your system (do not count your learn account)?
- What is your learn account's UID and GID?
- What is your learn account's home directory?
- What is the home directory for the user "root"?
- How do you determine the host name of your GNU/Linux workstation?
- What command can display the NIC's MAC address?
- Which file contains the default "runlevel" value for your GNU/Linux workstation?
Before moving your disk pack to another system, unbind your MAC address.