Posts Tagged ‘boot’
Boot arguments may include more than one string. All argument strings are passed to the secondary boot program; they are not interpreted by OpenBoot. If any arguments are specified on the boot command line, then neither the boot-file nor the diag-file nvram variable is used. The contents of the nvram variables are not merged with command line arguments.
For example, the command
ok boot -s
ignores the settings in both boot-file and diag-file; it interprets the string “-s” as arguments. boot will not use the contents of boot-file or diag-file. The commands
ok boot net
ok boot cdrom
have no arguments; they will use the settings in boot-file or diag-file, if they are set, as default filename and arguments and pass them to boot. Accordingly, if boot-file is set to the 64-bit kernel filename and you attempt to boot the installation CD with boot cdrom, boot will fail if the installation CD contains only a 32-bit kernel.
A. Common boot Syntax
ok boot [device-specifier] [arguments]
This behavior is found on most OpenBoot 2.x and 3.x based systems. Note that differences may occur on some platforms. Full Story
Installing required packages
RHEL 5 has the Kdump packages installed by default. If for any reason they are not installed, you need to install the packages “kexec-tools-.rpm” and “system-config-kdump-.rpm” with the following commands:
# rpm -ivh kexec-tools-.rpm system-config-kdump-.rpm
or, if your system is registered at the Red Hat Network, by running
# yum install kexec-tools system-config-kdump
Configuration of Kdump
First you need to enable Kdump. There is a configuration dialog available which can be started under a graphical environment by using:
Please check the option box “Enable kdump” at the top of the Dialog.
Next, you have to define the memory to reserve for Kdump In the dialog you see the memory information for your system and the usable memory for Kdump. On most systems a value of “128MB” Kdump memory should be enough.
Finally, you need to define a location where to store the dump file. You have the choice between “file”, “nfs”, “ssh”, “raw”, “ext2″, and “ext3″. This setup is straight forward, please configure the kdump as it fit’s best into your environment. The simplest configuration for the location is “file:///var/crash“.
You need to take care that you have enough disk space on the configured location, at least the physically memory of the system which is expected to dumped.
After you have configured kdump, you need to reboot the system to activate the settings.
More information about the configuration can be found in the file “/usr/share/doc/kexec-tools-*/kexec-kdump-howto.txt“