Top Ubuntu Preinstallation problems and fixes
Some problems might arise before you even boot Ubuntu's live distro mode in order to run the installation program. This article addresses such issues.
Problem
When I boot from the Ubuntu DVD-ROM, the drive spins up as if something is happening, but I see nothing. (Alternatively, I see on-screen graphical corruption.)
Solution
It's possible the DVD-ROM disc is either dirty or faulty. Examine its surface for scratches, or try cleaning it with a moist tissue. A typical indicator of a dirty or damaged disc is that the drive spins up and then instantly spins down several times in succession - listen to the whir of the drive's motor to tell if this is the case.
If the disc seems okay, it might be that your computer is unable to display the Ubuntu boot menu. To get around this, when you see the blank screen or graphical corruption, press the Esc key twice. Then press Enter. You'll see the word boot: at the top left of the screen, along with a prompt at which you can enter commands. Type live, and press Enter.
Problem
The computer boots from the DVD-ROM, but when the boot menu appears, pressing Enter doesn't start the installation. In fact, nothing happens at all! I'm unable to move up and down through the menu choices either - the keyboard is totally unresponsive.
Solution
If your PC uses a USB keyboard, it might be that it's not being recognized by the Ubuntu boot loader. To get around this, it's possible to make most computers pretend that USB keyboards are older PS/2 keyboards. This is done on a fundamental hardware level and is invisible to the operating system. Here are the steps:
1) Enter the BIOS setup program by pressing Delete during the initial stages of your computer's boot routine (while memory testing and drive identification are still taking place). Some computers might use a different key combination to enter BIOS setup, such as Ctrl+Insert, but this information will be displayed on your screen.
2) Use the cursor keys to navigate to the Integrated Peripherals section, and then look for an entry along the lines of USB Legacy Support. Set it to Enabled.
3) Press ESC to return to the main menu, and opt to save the changes.
4) Reboot the computer.
Note that you should repeat this procedure and deactivate USB Legacy Support once Ubuntu has been installed. At that stage, Ubuntu should be able to recognize the USB keyboard properly.
Problem
I'm using the same keyboard, mouse, and monitor across several computers, courtesy of a keyboard, video, and mouse (KVM) switch. When Ubuntu boots, the resolution is wrong and the graphics are corrupted. (Also, my keyboard or mouse doesn't work correctly.)
Solution
A KVM switch doesn't allow Ubuntu to correctly probe the attached hardware. Consider attaching the keyboard, monitor, and mouse directly to the computer for the duration of the installation.
Problem
After I've pressed Enter at the boot menu to start booting Ubuntu, the computer freezes and eventually displays a message along the lines of "Kernel Panic."
Solution
Kernel Panic errors occur when Ubuntu cannot continue to load for various reasons. In this context, it's likely that either the DVD is faulty (or dirty) or that your PC has a defective item of hardware.
First, check to make sure the DVD is clean and not scratched. If possible, try it on a different computer. If it works, then it’s clearly not at fault, and your computer most likely has a hardware issue. In particular, bad memory can cause problems. Does the computer already have an operating system installed? Does this run without problems? If not, consider replacing your memory modules.
To thoroughly test your computer's memory, boot from the Ubuntu DVD and select the Test Memory option on the menu (use the arrow keys to move up or down in the list, and press Enter to make a selection). This will run the Memtest86 program, and any problems with your memory will be reported in the Errors column on the right side of the program screen. For more details about how to use Memtest86, see www.memtest86.com.
Problem
Immediately after I press Enter at the boot menu to start Ubuntu’s live distro mode, the computer looks like it has crashed - the graphics are corrupted!
Solution
Your graphics card may be incompatible with the framebuffer graphical mode used by Ubuntu's boot routine. You can overcome this problem by following these steps:
1) Reboot the computer, press Escape, and then press F6.
2) You should see a line of text appear below the menu that begins Boot Options. Using the Backspace key, delete quiet splash -- from the end of the line. Then press Enter.
If you continue to see graphical corruption, try using the solution to the next problem.
Problem
When I select the Install Ubuntu option and press Enter, I see a status bar, but when the Ubuntu desktop should appear, it looks like my computer has crashed - all I see is graphical corruption.
Solution
Reboot the computer, and when the Ubuntu boot menu appears, select Ubuntu and press F4. Select Safe Graphics Mode, and then press Enter. This will start Ubuntu using VESA graphics drivers, which are compatible with practically every graphics card made within the last ten years.
If you're trying this solution after trying the solution to the previous problem. edit the Boot Options line first, as stated in the previous solution, and then press F4 and select Safe Graphics Mode.
Problem
After I've selected the Install Ubuntu option on the menu, the status bar appears, but then the computer freezes.
Solution
It's possible the power-saving feature or the advanced programmable interrupt controller (APIC) in your computer is causing problems. Press the F6 key, and after selecting the live or install option, type the following at the end of the Boot Options line that appears:
acpi=off noapic nolapic
Press Enter when you've finished to boot Ubuntu.
Problem
I'm attempting to install Ubuntu onto a notebook computer. After I select the Install Ubuntu option and press Enter, the screen is filled with graphical corruption, and it looks like Ubuntu has crashed. (Alternatively, the screen looks squashed, or some elements are off-center or off the edge of the screen.)
Solution
When the Ubuntu boot menu appears, press the Esc key twice and then press Enter. At the boot: prompt, type live vga=771. Then press Enter.
Problem
During booting, my computer hangs. On screen I see a lot of output, but at the bottom of it are the words aec671x-detect....
Solution
When the Ubuntu boot menu appears, press the Esc key twice and press Enter. At the boot: prompt, type live gdth=disable:y. Then press Enter.
Problem
The Ubuntu DVD-ROM seems to boot into the Ubuntu installer program, but then the screen goes blank, and my monitor flashes an error along the lines of "Cannot display this mode" or "Out of mode." (This problem might affect users of widescreen monitors in particular.)
Solution
It sounds like the graphical configuration Ubuntu automatically generates for your computer isn't correct. Reboot the computer, and when the Ubuntu boot menu appears, select Install Ubuntu, press F4, and then select Safe Graphics Mode. Then press Enter. This will start Ubuntu using VESA graphics drivers, which are compatible with practically every graphics card made within the last ten years.
Alternatively, it's possible that, although the screen is blank, the Ubuntu login screen is running in the background. You can, therefore, try logging in "blind" (that is, without any visual feedback on screen). Type your username, press Enter, type your password, and press Enter again. At this point, you may find that the desktop appears as it should. Then use the Screen Resolution program (System ➤ Preferences) to set the correct resolution and refresh rate.
Tags: drivers,framebuffer,kernel,kvm,memtest
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