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Appendix H. Additional Boot Options

remote display terminal and does not allow access from anyone or any system not specifically

authorized for remote access.

driverdisk

This command performs the same function as the

dd

command and will also prompt you to use

a driver disk during the installation of Red Hat Linux.

expert

This command will turn on the following special features:

allows partitioning of removable media

prompts for driver disk

ide=nodma

This command disables DMA on all IDE devices and may be useful when having IDE related

problems.

isa

This command prompts you for ISA device configuration.

lowres

This command forces the graphical (GUI) installation program to run at a lower resolution

(640x480).

mediacheck

This command gives you the option of testing the integrity of install source (if an ISO based

method). Verifying that the ISO images are intact before you attempt an installation will help to

avoid problems that are often encountered during an installation.

mem=xxxM

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 the only 16 MB is detected and for some new

machines where the video card shares the video memory with the main memory. When executing

this command, xxx should be replaced with the amount of memory in megabytes.

nmi_watchdog=1

This command enables the built in kernel deadlock detector. This command can be used to debug

hard kernel lockups. By executing periodic NMI (Non Maskable Interrupt) interrupts, the kernel

can monitor whether any CPU has locked up, and print out debugging messages as needed.

noapic

This command tells the kernel to not use the APIC chip. This command may be helpful for some

motherboards with a bad APIC (such as the Abit BP6) or with a buggy BIOS.

noht

This command disables hyperthreading (when available in SMP systems).

nomce

This command disables self diagnosis checks performed on the CPU. The kernel enables self 

diagnosis on the CPU by default (called Machine Check Exception). On some older Compaq

machines, this check is run too often and may need to be disabled.