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Frequently Asked Questions

This page goes over some of the basics of using Linux, and a few basics of using Fedora in particular. It's helpful to know these things before reading the Unofficial FAQ.


Some Linux Basics

What is a terminal? How to I "open a terminal?"

A "terminal" is a way of typing commands to the computer. That may sound very strange, but it's actually really, really nice and easy once you get used to it. You can use Fedora as a totally graphical system, or you can use it totally with the terminal. I like to do both; I use whichever one is easier for the task I'm doing.

You can either open a terminal inside of your graphical environment, or you can switch your whole screen to a terminal.

To open a terminal in a graphical environment:

1. Open up your menu. This is either the "Red Hat" down in the tray, or a little "foot," or possibly a little penguin. 2. Under System Tools, click on Terminal.

To switch your entire screen to a terminal, press Ctrl-Alt-F1. You can then switch between six different terminals, by using Alt-F1 through Alt-F6. Pressing Alt-F7 will bring you back to your graphical environment.

What is root? How do I "become root?"

"root" is the name of the user who can control everything on the entire computer. We call this the "super user."

To become root, first you must Open a terminal . Then, you type:

su -

Note that the "-" is very important -- it sets things so that you have easy access to all the commands on the computer.

Then, you have to type in your root password. You set this when you installed Fedora.

If you're using the "open a terminal" method where you make the whole screen into a terminal, then you just need to put "root" as your "Login:" name, and then enter the correct password.

I installed a program, how do I start it?

First, look around in the "Red Hat" menu in the toolbar. Most new programs installed will add themselves to the menu automatically.

If you can't find it in the menu, you can use the Terminal, in the menu under "System Tools." Most programs are executed by their name. For example, to launch the web browser, mozilla, you can simply open a terminal and type:

mozilla

If it isn't in the menu and the program name isn't obvious, try this to list the programs in a package:

rpm -ql packagename | grep bin

What is a runlevel?

A runlevel is a number which indicates what "mode" you want to computer to boot into. For example, runlevel 5 is graphical mode, where runlevel 3 is text-only mode. Runlevel 1 is "single-user" mode, used for troubleshooting problems.

There are three ways to change your runlevel:

  • While the Computer is Running:

1. Open a terminal . 2. Become root . 3. Type:

init number
where number is the runlevel that you want to change to.

You will then be switched into the new runlevel.

  • While You Are Booting the Computer:

1. When you first start your computer, the GRUB screen (where you choose your Operating System) appears. Select the Fedora that you want to boot into, but press the a key instead of pressing Enter.

2. You will see a line somewhat like the following: kernel /vmlinuz-2.6.9-1.667 ro root=LABEL=/ acpi=on rhgb quiet
Add the number of your runlevel to the end of that line, and then press Enter. For example, to boot into text-only mode, the line would look like: kernel /vmlinuz-2.6.9-1.667 ro root=LABEL=/ acpi=on rhgb quiet 3
You will then boot into the new runlevel this time only.

  • Permanently Set a Default Runlevel:

1. Open a terminal . 2. Become root . 3. Open the file /etc/inittab in your favorite text editor. gedit /etc/inittab

4. Find the line: id:number:initdefault:
where number is your current default runlevel (probably 5). 5. Change the number in the middle of the line to the new runlevel that you want your computer to start in by default. For example, if you want to start in text-only mode by default, change it to: id:3:initdefault:
You will then boot into that runlevel every time you start the computer.

(Thanks to Ilja Kogan for the inspiration to write this question, and some original text.)

How do I start in text-only mode (no graphical environment)?

Text-only mode is runlevel 3. If you want to start in text-only mode, see the instructions in the runlevel question above, and change your runlevel to runlevel 3.

How do I run something when the computer starts?

You have two choices, either you can run something before anybody logs in, or you can run something immediately after you log in.

To run a command right after you boot, before anybody logs in, add the command to the file /etc/rc.local:

1. Open a terminal . 2. Become root . 3. Open the file in your favorite text editor:
gedit /etc/rc.local 4. Add the command that you want to run to the end of the file, on its own line.

If you want to start a program right after you log in:

1. Log in. 2. Wait for everything to start, then start only the program that you want to start automatically from now on. 3. Log out, and put a check in the "Save Settings" box.

From now on, when you log in, that program will be automatically started. If you want to stop that program from starting automatically, just:

1. Log in. 2. Quit the program that you want to no longer automatically start. 3. Log out, and put a check in the "Save Settings" box.

The "Save Settings" check box just causes your system to always look, by default, exactly like it does right before you log out.

(Thanks to Ilja Kogan for the question suggestion and original text.)

How do I reset my root password?

If you've forgotten your root password, and you want to change it, don't worry! It's possible. You need to boot into what's called "single-user mode." You must be in front of the computer to do this -- you can not do it remotely:

1. Using the instructions in the runlevel question (under the "While You Are Booting the Computer" section), boot into runlevel 1. 2. Set the new root password with by typing:
passwd
And then enter your new root password when asked. 3. Reboot your machine, and you will now be able to log in as root with the new password that you entered.

(Thanks to Mark Senn for suggesting that I write this question and giving me some original text.)

Some Fedora Basics

What is a "service?" How do I manage services in Fedora?

A "service" is a program that starts automatically when you start your computer, and runs in the background. For example, the "network" service sets up your connection to the Internet and keeps it running correctly.

There are two ways to manage services in Fedora, one using the graphical tools, and one using only the command line. If you're not in a graphical environment, use the command line method.

Using the graphical tool which can be found in the menu, under System Settings - > Server Settings - > Services:

  • Check if a service is running: Select your service in the list, the status is shown in the status section.
  • Starting a service: Select your service in the list and press Start.
  • Stopping a service: Select your service in the list and press Stop.
  • Have a service start automatically at boot: Select your service in the list, check the checkbox next to it.
  • Stop a service from starting automatically at boot: Select your service in the list, uncheck the checkbox next to it.

Using the command line (replace servicename with the name of the servive you want):

You must be root for this to work.

  • Check if a service is running:

service servicename status

  • Starting a service:

service servicename start

  • Stopping a service:

service servicename stop

  • Have a service start automatically at boot:

1. Open the ntsysv program:
ntsysv 2. Find your service in the list and press space to enable it. Services marked with a * will start automatically at boot.

  • Stop a service from starting automatically at boot:

1. Open the ntsysv program:
ntsysv 2. Find your service in the list and press space to disable it. Services marked with a * will start automatically at boot.

(Thanks to Sindre for the original text of this question!)

What is rescue mode and how do I boot into it?

Rescue mode provides the ability to boot a small Fedora environment entirely from a CD-ROM or USB drive instead of the system's hard drive. As the name implies, rescue mode is provided to rescue you from something. In rescue-mode you can mount and edit your files, such as configuration files and by doing so solve your problems.

To boot into rescue mode, you must be able to boot the system using one of the following methods: 1. By booting the system from an installation boot CD-ROM, or a boot image on a USB disk. 2. By booting the system from the Fedora CD-ROM #1. Once you have booted using one of the described methods, enter the following command at the installation boot prompt:

linux rescue