D.1.1. Are You Unable to Boot from the CD-ROM?

	Note
	There are a few cases where the system BIOS does not allow the Red Hat Linux CD-ROM to boot because of the size of the boot image on the CD-ROM itself. In cases such as these, a boot diskette should be made to boot Red Hat Linux. Once booted, the CD-ROMs work properly for the installation.

If you cannot boot from your Red Hat Linux CD-ROM, you have two options:

1. You can change your BIOS so that booting from the CD-ROM is recognized first in the boot order, or

2. Boot using a boot diskette you have created.

To change your BIOS, refer to your system manual for the correct keyboard combination that allows you to access your BIOS, or you can read the key sequence needed while the system begins to boot (assuming it is displayed).

To create a boot diskette, follow the instructions in Section 1.4.3 Making an Installation Boot Diskette.

To boot Red Hat Linux using a boot diskette, insert the diskette you have created into your diskette drive and then boot/reboot your computer. Make sure that your BIOS is set to use the diskette or removable diskette to boot.

D.1.2. Are You Unable to Boot from a Boot Diskette?

If you cannot boot from a boot diskette, you have two options:

1. You can change your BIOS so that booting from the boot diskette is recognized first in the boot order, or

2. You can boot using an updated boot diskette image.

To change your BIOS, refer to your system manual for the correct keyboard combination that allows you to access your BIOS, or you can read the key sequence needed while the system begins to boot (assuming it is displayed).

To find an updated boot diskette image, check the online errata at

http://www.redhat.com/support/errata

and follow the instructions in Section 1.4.3 Making an Installation Boot Diskette, to make an updated boot diskette for your system.

D.1.3. Is Your System Displaying Signal 11 Errors?

A signal 11 error, commonly know as a segmentation fault, means that the program accessed a memory location that was not assigned.

If you receive a fatal signal 11 error during your installation, it is probably due to a hardware error in memory on your system's bus. A hardware error in memory can be caused by problems in executables or with the system's hardware. Like other operating systems, Red Hat Linux places its own demands on your system's hardware. Some of this hardware may not be able to meet those demands, even if they work properly under another OS.

Check to see if you have the latest installation and supplemental boot diskettes from Red Hat. Review the online errata to see if newer versions are available. If the latest images still fail, it may be due to a problem with your hardware. Commonly, these errors are in your memory or CPU-cache. A possible solution for this error is turning off the CPU-cache in the BIOS. You could also try to swap your memory around in the motherboard slots to see if the problem is either slot or memory related.

You can also try running the installation with only 64MB of memory. This can be done by booting the installation program with the mem=64M boot option. To try this option, at the installation boot prompt, type

boot: mem=xxxM

where xxx should be replaced with the amount of memory in megabytes.

This command allows you to override the amount of memory the kernel detects for the machine. This may be needed for some older systems where only 16MB is detected by the installation program (but more RAM is present in the system), and for some new machines where the video card shares the video memory with the main memory.

Another option is to perform a media check on your installation CD-ROMs. To test the checksum integrity of an ISO image, at the installation boot prompt, type:

boot: linux mediacheck

For more information concerning signal 11 errors, refer to:

http://www.bitwizard.nl/sig11/