You could work around this by plugging in a monitor, mouse, and keyboard and letting the OS boot and then removing the monitor when the boot process has finished. This is a far from ideal solution. Fortunately the Linux community has come up with a temporary work around for this issue (I’m confident the distribution developers will come up with a much better solution soon). Let’s take a look at the solution.

Warnings

This solution requires that you create an /etc/X11/xorg.conf configuration file. I assume that anyone wanting to set up a headless server isn’t afraid of manually creating/editing the xorg.conf file. If you are, make sure you back up any pre-existing xorg.conf file that might live in /etc/X11.

This guide also assumes that you already have a working server installation that you can successfully boot with an attached monitor. I will also assume you know what graphics card is in your server. You will need this information momentarily (so if you don’t know it, dig around and find out what card you are using). With that being said, let’s get on with it.

xorg.conf

The first thing you need to do is to set up the xorg.conf configuration. If one already exists, copy it to /etc/X11/xorg.conf.OLD and then erase the contents of the /etc/X11/xorg.conf file. The new contents of that file will be:

Section "Device"
Identifier "VNC Device"
Driver "vesa"
EndSection

Section "Screen"
Identifier "VNC Screen"
Device "VNC Device"
Monitor "VNC Monitor"
SubSection "Display"
Modes "1024x768"
EndSubSection
EndSection

Section "Monitor"
Identifier "VNC Monitor"
HorizSync 30-70
VertRefresh 50-75
EndSection

Once you have saved and closed that file you now need to edit the /etc/default/grub file and add the following line:

GRUB_CMDLINE_LINUX="nomodeset"

You can take this one step further and disable the splash screen for the boot process by setting the line:

GRUB_CMDLINE_LINUX_DEFAULT=

to “quiet” instead of “quiet splash”

Save the /etc/default/grub file and then issue the command sudo update-grub to rebuilt grub.

To test this setup go ahead and boot the machine without the monitor attached. Once you have given it plenty of time to boot you can either VNC or ssh into the machine. If you get a successful connection you are good to go. If you do not get a successful connection plug the monitor back in and see where in the process it stopped. If you have a black screen revisit the configuration and make sure everything is correct. To further troubleshoot boot the machine with the monitor plugged in and check the /var/log/Xorg.0.log file for any errors. Hopefully you will find the setup above works like a champ.

In this article I am going to show you the steps in both Fedora 13 and Ubuntu 10.04 to get this combination back. It’s actually an easy process, you just have to know the precise places where to look for the configurations.

A word of warning

The main reason why the distributions removed this combination is they didn’t want unsuspecting users to accidentally kill their running X server. I get this. But for those of us who aren’t so prone to accidentally killing the X Server, having this back is a good thing. For those who are prone to mistakenly hitting combinations like CTRL-ALT-Backspace, well, you might want to leave this feature disabled.

Fedora and Ubuntu 10.04 in GNOME

Figure 1

Let’s first take care of Fedora 13. First I will show you how to do this in the GNOME environment. It’s done the same way in both distributions. The first thing you need to do is click System > Preferences > Keyboard. In this new window click on the Layout tab and then click on the Options button. In this new window (see Figure 1) expand the entry for Key sequence to kill the X server. Once you expand that you will see the entry for Control + Alt + Backspace. Make sure that entry has its checkbox checked and then close the window.

You can now close the Keyboard preferences window and you can now enjoy having CTRL-ALT-Backspace back.

But what if you are a KDE user? Let’s take a look.

KDE

Figure 2

The process of gaining this behavior back in KDE is equally simple (though not as quick). The first step is to click Start > Computer > System Settings which will open up the System Settings window. Now click on Regional & Language. In this new window you must first click the Keyboard tab and then check the box for Enable Keyboard layouts (see Figure 2). Once you have done that you can then click on the advanced tab.

In this new window expand the entry for Key sequence to kill the X server and then make sure Control + Alt + Backspace is checked. Once done with that click Apply and then you can close the System Settings window.

You now have your CTRL-ALT-Backspace back in KDE!

Final thoughts

I do get why the distributions saw to it to disable this feature. But I am glad they made it possible to bring it back. And now, for those of you who want it, you can have the ability to kill and restart your X server with a three-finger salute!

There is one problem that can arise when using a KVM switch with a modern Linux distribution. This problem has to do with the latest releases of Xorg. Because Xorg no longer uses the xorg.conf file, it depends upon receiving identification signals from the monitor in order to automatically adjust the display. On a single system/single monitor setup this works perfectly. But in some instances a KVM switch will get in the way and the X Windows display will be far from ideal (and some times not even usable). How do you get around this situation? In this article you will read a few tips that will help you get around this.

Choosing your KVM

There is, unfortunately no way to know which KVM switch will work well with modern Linux setups. I have tried four different KVM switches with modern Linux distributions – all with varied results. Here are the KVMs I have used (and their results):

• Belkin Flip (USB): Switched between machines quickly, but lead to freezing with Ubuntu Linux. Couldn’t detect monitors so resolution was poor.
• IO Gear Miniview 2-port (USB): Switched between machines quickly, no freezing. Couldn’t detect monitors so resolution was poor.
• Generic 4-port KVM (USB – purchased on Ebay): Poor switching, constant freezing, and couldn’t detect monitor.
• IO Gear 4-port Miniview (USB): Easy switching, no freezing, monitor detected so resolution was perfect.

So from the above list, you would obviously want to go with the IO Gear 4-port miniview. It’s an inexpensive solution (approximately $70.00 USD) that will give you no problems.

Using your current KVM

What if you already have a KVM switch? There are options. The first option is to manually configure your /etc/X11/xorg.conf file (For more information on the xorg.conf file check out the xorg.conf articles on Ghacks.net). This can lead to problems when you’re not sure what your graphics card is or the resolution of your monitor. Because of this, you might have to do a bit of research before you continue. If you know you are using an NVidia card you are lucky, you can use the Nvidia Settings tool (read about it in my article “Adding  a widescreen monitor in Linux“.) You can use this tool to generate your xorg.conf file for you.

If you do not want to have to monkey around with configuring xorg.conf, you have another solution – one that isn’t perfect, but will work in a pinch (and one I have used when dealing with certain on-board graphics chips like Intel). Plug your  monitor, keyboard, and mouse directly into your Linux machine and let it boot. Once you have your desktop up and running unplug the monitor, keyboard, and mouse and plug them back into the KVM. Plug the KVM cords into your Linux box and your Linux machine will be up and running. Fortunately the Linux machine won’t have to be rebooted for anything any time soon. It’s not an ideal solution, but it will work for you. Just remember, if you have to reboot you need to switch those cables around until the machine is back to the GUI desktop.

Final thoughts

Ideally you will purchase a KVM switch like the IO Gear 4-port Miniview that will give you no problems. Otherwise you might have to toy with a work-around or two in order to get your Linux box working with your KVM. This is the price the user-community has to pay for having a modern distribution that doesn’t require configuring X (at least not single-system setups).

Some of these terms might seem very basic to a few readers and some of them not so basic. It is important, however, that we are all standing on common ground and not having to “google” a term all the time. This article will not be exhaustive, it will cover a few terms. In later “Get to know Linux” articles we will cover more of these terms. Without further adieu, let’s proceed.

~/ or users’ home: This is the directory, created when you either install your operating system or create a new user (with the right arguments), that holds all of your personal data. This directory is created based on what is in the /etc/skel directory. This is the one directory your user has full permissions in. From the command line, the fastest way to get to this directory is to enter the command cd.

Kernel: This is the heart of Linux. In fact some purists will tell you that this IS Linux and everything else is nothing more than various applications built to run on top of Linux. The Linux kernel is a true preemptive multi-tasking kernel, is written in C, and is the single largest “application” on your system. Without the kernel you would not have a Linux operating system. “Back in the day” you would hear Linux users talk about “rolling their own kernel” or “compiling their own kernel”. This referred to building a kernel to meet specific needs. At one time this was almost a necessity for many users. This is not so much the case now as the modern kernel contains just about everything you would need.

Distribution: A distribution of Linux is a bundled variation of Linux. There are a number of major distributions such as: Ubuntu, Fedora, SuSE, Debian. There are also a far greater number of minor distributions: PCLinuxOS,  Linux Mint, Elive, Gentoo, etc. Each distribution has its own selling point. For example: Ubuntu is one of the best known distributions for new users. On the other hand of the spectrum, Gentoo is for highly experienced users. You will often here the term “distro” used in place of “distribution”.

Terminal, Console, or Terminal Emulator: This is where commands are entered. There are really two places this is done: In a terminal window or a Console. Often these terms are exchanged, but there is a difference. A terminal window is generally a small application (like gnome-terminal or xterm) that allows you to enter commands. The console is actually the command line version of the Linux interface. To get to what is typically called “console mode” you would either have to go to a virtual console (using <Ctrl><Alt>F1-0) or log out of X and kill your graphical log in (such as gdm). When your monitor shows nothing but your bash prompt, you are in “console mode”.

X: This term stands for X Window System. In simplest terms, X provides the graphical interface for Linux. Of course it is much more complex than that. The X Windows system alone wouldn’t offer you much functionality as X only provides the framework for the GUI. Running only X would give you a grayish screen, a cursor, and not much more. What you don’t see is that X provides the very foundation that enables your window managers and desktops to do what they do. You will often here the phrase “Log out of X” which, for the purposes of the end user, means log out of your desktop.

Package Manager: One of the key selling points for distributions is which package manager they use. A package manager is the system which applications are automatically installed, removed, and generally managed on a system.Two of the major package management systems for Linux: dpkg and rpm. The dpkg was originally for Debian systems but is now employed by Ubuntu and others as well. RPM was created for the Red Hat Linux distribution but now is used by Fedora, SuSE, and others. Each of these systems have both command line tools (such as apt and apt-get for dpkg, and yum for RPM) and GUI tools (such as gpk-application for RPM and Synaptic for dpkg).

Final thoughts

There you have a few of the terms you should be familiar with when using the Linux operating system. We will continue with more terms at a later date. If you would like to request terms to be defined (or if you would like to request a Linux topic in general), please feel free to contact me.