|
|
This section takes you through common (and some uncommon) failures that can occur during installation and provides advice to get through those problems.
| Note |
Many of the features for installing Fedora Core or Red Hat Linux are described in detail in Red Hat Linux Bible. If you are not familiar with techniques for installing over the network, creating install servers, making boot floppies, doing kickstart installations, and other installation topics, you can find these and other installation topics covered in Red Hat Linux Bible. Information on doing kickstart installations is included in Chapter 4. |
There are some cases where you don't even make it to the boot: prompt on the installation screen. If that's the case, here are a few things you can try:
CD drive not booting-Some computers are not set up to boot from a CD. This is more often true of older PCs where you were expected to boot from a floppy disk. You can often fix this problem by changing the BIOS.
To change the BIOS, boot the computer and look early on for a message that tells you how to enter setup (usually by pressing Del, F1, or F2). After entering setup, look for a place to change the boot order so that your CD drive is first on the list of media to boot (at least, before hard disk).
CD drive not found-It is possible that the installation process might be able to boot the CD from your IDE (ATAPI) CD drive, but not find the drive when it goes to install Fedora. To get around this problem, you can identify the CD drive from the installation boot prompt. For example, if your CD driverwere the slave drive on your first IDE controller, you could enter the following line to identify your CD drive:
boot: linux hdb=cdrom
The master on the first IDE controller would be hda; the master on the second IDE controller, hdc; and the slave on the second IDE controller would be hdd.
Not bootable CD drive-If there is no way to make your CD drive bootable, you can create a bootable floppy disk image from the Red Hat Linux or Fedora installation media. You can find the bootable floppy disk images on the first Fedora Core CD in the images directory. The README file in that same directory provides a brief description of each image.
No bootable CD drive or floppy-An even slimmer possibility is that you have a computer with a nonbootable CD drive and no floppy disk drive at all. In that case, you might be able to boot installation from MS-DOS (that's MS-DOS directly and not from a DOS window in Windows). With DOS running, insert the CD into the CD drive and type the following:
C:\ > D: D:\ > cd \ dosutils D:\ DOSUTTLS> autoboot.bat
Another alternative if your computer has a network connection is a Preboot eXecution Environment (PXE) install. To be able to do a PXE install, you must first set up a boot server to let the client boot the necessary install image. (PXE install images are contained on CD 1 for Fedora and Red Hat Linux systems in the images/pxeboot directory.) Then set up an install server (as described in Red Hat Linux Bible). If PXE support is built into the network interface card on the machine you want to install from, you can enable PXE in that computer's BIOS. When you boot the computer, select to boot from PXE. When prompted, identify the install method you want to use, and continue as you would with any network install.
| Note |
There is a white paper from HP on doing a PXE install. You can find it here:http://h18000.www1.hp.com/products/servers/linux/redhdt-whitepapers.html. The Linux on an IBM ThinkPad page (www.solarblue.net/docs/x31.htm) provides a good description of how to do a PXE install, including how to set up the PXE boot server. |
No CD drive-If there is no CD drive on the computer, you can install from any of several other media types. By first creating a floppy boot disk (as mentioned in the previous point), you can install from software that is located on an HTTP, FTP, or NFS server. An ethernet card is required for each of those network install types. If you can get copies on to the hard disk, you can install from that medium as well.
Checking media-The media could be so bad that you may not even get to a boot prompt. To find out if the medium is truly damaged beyond repair, try inserting the first boot CD into any running computer (Linux or Windows) and try to browse the contents of the CD. If you can access the CD and some of the files on that CD, chances are that you should be able to boot the CD. (The CD could still be corrupted, but you can find that out with a media check when you boot the install process.)
Screen is unreadable-My first suggestion to installing on a machine where the GUI is unreadable is to run the installation in text mode:
boot: linux text
Some experienced system administrators prefer text-based installs because it allows them to deal with their video cards after the operating system is installed. Instead of having the system boot to runlevel 5 with a GUI that may or may not work, the computer will boot runlevel 3 (text login prompt) and let the administrator get the GUI going on a working system.
| Note |
I always do a text-based install when I have an NVIDIA-based card since I know I'm going to replace the video driver after installation with an NVIDIA proprietary driver. |
If you are having trouble with the screen not being readable in text mode, there are some ways of telling the install process something about your graphical hardware. See the description of the vga= option earlier in this chapter for further information.
If you are able to successfully boot the Fedora Core or Red Hat Linux CD, you should see the installation boot screen (with a boot: prompt at the bottom). In most cases, you will choose from one of the following two installation types:
Graphical installation-If you just press Enter (or wait a few seconds for it to start automatically), Fedora Core 1 will start up the graphical installation process and expect to install the software from the three-CD set. This is the default way to install Red Hat Linux systems.
Text-based install-If you have a low memory computer, unsupported graphics card, or simply don't feel the need for colors and icons, you can do a text-based install. To start a text-based install, type linux text from the boot prompt.
Starting the installation process essentially means booting a small Linux kernel that, in turn, runs the Anaconda installer. Because you are starting an install process, there are several different install-related options you can add to direct how the installation process should behave. Likewise, you can also pass options to the kernel that can specifically tell the kernel about how to deal with your hardware (especially if the installation process is unable to properly detect your hardware).
The following points describe different problems that can arise during installation and that you might be able to correct by trying different options from the installation boot prompt.
Corrupted CDs-Before you install Fedora Core or Red Hat Linux from CD, you can verify that the contents of the CD have not been damaged by running mediacheck from the boot prompt. Even if you have no reason to suspect that the CDs are bad, checking the entire set of CDs can help you avoid having to deal with a partially completed installation.
The mediacheck performs an md5sum checksum of the contents of any of the Red Hat installation CDs you provide. Because the exact same content (an ISO image) is used in an NFS or hard disk install, mediacheck allows you to validate those installation media as well. To start mediacheck from a boot prompt, type
boot: linux mediacheck
CD-ROM installation hangs transferring disk image-When booting from a CD, it is possible that your computer will hang with the message "Transferring Install Image to Hard Disk." There are two recommended courses to try: Turning on DMA for your CD or turning it off completely for your system. To turn on DMA for your CD, type the following from the installation boot prompt:
boot: linux allowcddma
| Note |
To run the same option for a text-based install, type linux text allowcddma. This also applies to any other option you want to add to a text-based install type. |
To try turning off DMA (during installation at least) to fix the problem, type the following at the boot prompt:
boot: linux nodma
With DMA turned off, installation will go slower, but failures may be less likely to occur. After Linux is installed, you may want to remove the nodma option from the /boot/grub/grub.conf file to see if your computer can run with DMA on (to improve performance).
One reported fix for this problem is also to reduce the amount of memory on computers (either by physically removing one of the RAM sticks or by making less memory available using the mem= option). See the Selecting Memory Sizes section later in this chapter for information on the mem option.
Hangs when installing on SMP system-If your computer hangs while trying to install on a system with multiple processors, you can try disabling IO-APIC. The noapic option causes an SMP kernel to disable some interrupt controller features on multiprocessor computers. Here's how to disable 10-APIC:
boot: linux noapic
If your board doesn't create a working multiprocessor table, you might be able to create one manually using the pirq boot option. For information on how to do this, refer to the I0-APIC.txt file in the /usr/src/linux-2.*/Documentation directory.
Hangs probing PCMCIA devices-You can disable the probing of PCMCIA devices by adding the nopcmcia option as follows:
boot: linux nopcmcia
Hangs probing Firewire devices-You can disable the probing of Firewire devices by adding the nofirewire option as follows:
boot: linux nofirewire
Hardware not detected (or improperly detected)-The Anaconda installer does an amazingly good job of probing and identifying your computer's hardware. However, if you have reason to suspect that your hardware is not being properly identified, you can boot using the noprobe option.
Before you start a noprobe install, you should know what hardware you have in your computer. If the drivers are not on the CD, you need to have the drivers you need available on floppy. Here's how to start a noprobe install:
boot: linux noprobe
When prompted, you need to select the drivers to match your hardware or provide the drivers yourself on a floppy.
No floppy to start network or hard disk install-Earlier releases of Red Hat Linux required that you create a boot floppy to start an FTP, HTTP, NFS, or hard disk install (assuming, I suppose, that if you have a CD-ROM drive you can just install from there). In Fedora Core 1 (and other recent Red Hat Linux distributions), you can start a network or hard disk install from the first installation CD boot prompt using the askmethod option as follows:
boot: linux askmethod
After entering your language and keyboard type, the installation screen asks you to select the type of install (HTTP, FTP, NFS, or hard disk). You might want to do this to save yourself from the trouble of inserting each CD.
Unable to upgrade-Any change to the /etc/fedora-release or /etc/redhat-release files (depending on which system you are upgrading from) may cause the upgrade process to fail to offer you the chance to upgrade your system to your chosen version of Fedora. If that is the case, you can force Fedora to allow you to upgrade by entering the upgradeany option at the boot prompt as follows:
boot: linux upgradeany
There are literally hundreds of options you can pass to the kernel when you begin installation. While we go over some of those options here, you can find a more complete list in the documentation that comes with the kernel source code. For Fedora Core 1, refer to the following file for descriptions of kernel options:
/usr/src/linux-2.*/Documentation/kernel-parameters.txt
Options you can pass to the kernel are also described, in some detail, in the BootPrompt HOWTO. You can find that document here
Documentation associated with particular drivers can be found in files and subdirectories of the /usr/src/linux-2*/Documentation directory. For the most part, you will not need to add module-specific options to the installation boot prompt. Special settings that need to be done to individual drivers can be done after installation (see Chapter 6 for information on adding loadable modules).
| Caution |
While most options that you can pass to the kernel from the boot prompt will cause no harm, some have the potential for damaging your hardware. For example, some improper video settings can damage your video card and options that effect CPU activity (such as no-hlt) can result in overheating. |
In most cases, you don't need to enter any kernel options to get the Fedora or Red Hat Linux installation to work. Hardware will be detected properly and same defaults will be set. However, cases where you would want to add kernel parameters include the following:
Not able to probe-In some cases, the kernel is not able to properly identify the hardware you are using or fully determine the features it does or doesn't support.
Extra tuning-Some options that can be passed to the kernel can be used to tune your kernel to make most efficient use of your hardware.
Override the defaults-You may want to access hardware in a different way than it is used by default (for example, to change the default screen resolution).
Once you find kernel options that work during installation, write down those options. You may need to add those same options to the kernel boot process after Fedora or Red Hat Linux is installed so that your system can boot properly (see the Adding Kernel Options After Installation section later in this chapter).
The following sections break down different kernel options you can use at the boot prompt for Fedora and Red Hat Linux installation.
Sometimes CPU bugs, old BIOS limitations, and other issues can prevent Linux from properly detecting the amount of memory available on your computer. Not having all available memory useable by the install process can considerably slow down the install process. The cachesize= and mem= options can be used to tell the kernel how much memory to use during the install process.
| Note |
Before you start installing, you can test the amount of available memory using the mem-ory test feature. See the Random Access Memory section earlier in this chapter for information on using the memtest feature from the installation boot prompt. |
Set CPU cache size-If the kernel can't determine the cache size correctly from the CPU (typically because of a CPU bug), you can override the level two CPU cache size and enter the proper amount in kilobytes. Here's an example where the level two cache is set to 512kB:
boot: linux cachesize=512k
Be sure to not set this number higher than the actual available level two CPU cache size.
Set memory size-If you have added memory to an older machine (beyond the 64MB limit originally defined in PC BIOS), the boot process may not detect that fact. Using the mem= option, you can set how much memory the kernel has available to it. Don't set this number higher than the actual amount of RAM available or your computer will crash at some point.
The hlt instructions tell CPU to change modes to use less power. The CPU essentially goes to sleep during some periods of disuse. Some older processors, particularly 486 processors, had problems coming out of this low-power mode. If you think this is the case for you, try entering no - hlt to the linux boot prompt as follows:
boot: linux no-hlt
One downside to using the no-hlt option is that the CPU stays on continuously. This could cause the CPU to overheat, especially in situations where you are overclocking the processor.
Some laptops have bugs in battery query support. If the machine crashes while entering a graphical install, you can try turning off advanced power management support as follows:
boot: linux apm=off
When you create the disk partitions on which you install your Fedora or Red Hat Linux system, you need to make sure that those partitions provide enough space not only for the current installation, but also for the space you need for data. Here are some tips related to partitioning your hard disk:
Allow enough total space-An Everything installation of Fedora Core 1 can take up about 5GB of disk space. So, you need to allow at least that much space plus room for your data if you do a complete installation.
Allow enough space for installation on each partition-If you separate your hard disk into multiple partitions to keep areas of the files system, be sure to allow enough space in each partition to handle the data needed. For example, some parts of the file system you may want to assign to their own partitions are /bin, /var, /home, /usr, and /tmp.
If you have 5GB available for a full install, but separate that space evenly across several partitions, chances are you will not have enough disk space where you need it. For example, /usr can require most of that 5GB of disk space itself, while /bin may require about 5MB of disk space.
Allow enough space for data on each partition-If you are splitting up partitions on your hard disk, be sure that you have taken account of the amount of space you need for data. Typically, content for your Web server, FTP server, and other data servers are contained under your /var directory. User data tends to be store under the /home directory.
Allow for overhead-An ext3 journaling file system (the default file system typed used by Fedora and Red Hat Linux systems), requires about 30MB of overhead for each partition. You need to take that into account if you are creating multiple partitions for your Linux installation.
The /boot partition-Although a 100MB partition is recommended for Fedora, you can get by with a much smaller boot partition if you are tight on space. A typical bootable linux kernel will consume between 1 and 4MB of disk space. So even with several different kernels, if the space is tight you can probably get by with as little as 20MB of space in /boot.
|
|