Graphical Installation
One of the most common problems you’ll encounter is video corruption in graphical-installation mode or upon first boot after installation. Here’s one way to escape from a corrupted Xwindows environment:
Ctl – Alt – Backspace
This will kill Xwindows and return you to a terminal. Actually, you’ve been there the whole time; you’ve just been working in a graphical subenvironment.
You always have several terminals available to you. You can switch between terminals like this:
Ctl – Alt – F2
Or F3 or F4. When you’re running Xwindows you’re “in” F7, so you can use that Function key to return to your graphical environment. Do note, however, that if you try to run startx you’ll get an error; X is already running!
One of the primary reasons for bad video is frame buffering. When you’re at the boot: prompt, rather than hitting Return or entering linux then Return, use this command:
boot: linux nofb
This disables framebuffer support. You could also force a 640×480 resolution:
boot: linux lowres
Finally, you can force a text-mode installation:
boot: linux text
Abnormal Terminations of Installation
There are a handful of problems that can all give you a “fatal error 11” and a crash during installation.
Fatal error 11 is a memory segmentation fault, which is vaguely similar to a buffer overflow: both result from software writing to memory it doesn’t own.
Sound like a software error? Actually it’s often a RAM error. If you’re running RAM that’s rated slower than your motherboard’s maximum, you will likely need to change some settings in your BIOS.
- Turn off CPU cache memory
- Increase the number of wait states
- Get faster RAM
Failure to Install the Boot Loader Properly
This is the infamous “1024 cylinders” problem: your boot loader is beyond those cylinders accessible by the BIOS.
Either:
- Make sure your / partition starts before cylinder 1024 (somewhere before the 8 GB mark), or
- Set up your /boot partition as the first partition on the disk.
Troubleshooting Problems After Installation
Installation Log Files
To see the list of packages that were installed: /root/install.log
To see a list of system events that occurred during installation: /root/install.log.syslog
The /proc directory
Do a listing of /proc. There are two kinds of items here:
- process information (numbered directories), and
- kernel parameters.
A tremendous lot of information is available to you in this directory.
CPU Info
cat /proc/cpuinfo
RAM Info
cat /proc/meminfo
DMA, IRQs and IO Ports
cat /proc/dma
cat /proc/interrupts
cat /proc/ioports
Kernel Modules
cat /proc/modules
dmesg
dmesg
dmesg | tail
Boot Logs
View a list of system processes, and whether they started successfully or not.
more /var/log/boot.log
tail /var/log/boot.log
Don’t forget that logs are rotated! The most recent archived log is boot.log.1, and older log files are boot.log.2, boot.log.3, etc.
Linux Rescue
One good way to get into a damaged system is using the linux rescue command when you get to the boot: prompt after booting the first distro CD.