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12 Tools To Decrease Website Load Times
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kdump-config(8) Linux System Administrator's Manual kdump-config(8) NAME
kdump-config - configure kdump, check status, or save a vmcore file SYNOPSIS
kdump-config { help | test | show | status | load | unload | savecore } DESCRIPTION
kdump-config manages the kdump feature of the Linux kernel. When a kdump enabled kernel panics, it immediately boots into a clean kernel called the kdump kernel. The memory image of the panicked kernel will be presented in /proc/vmcore while the kdump kernel (or "capture kernel") is running. kdump-config loads the kdump kernel into the current kernel and after a kdump, captures the vmcore image via kdump kernel. kdump-config can take advantage of the linux-image-$(uname -r)-dbg package and will try to use makedumpfile to capture the vmcore. The crash tool can then be used to analyze the vmcore at a later time. kdump-config exits with 0 on success and 1 on failure. COMMANDS
help Print a usage summary. test Determine the parameters that would be used to load the kdump kernel, but do not load the kdump kernel. Useful for evaluating your configuration settings. show Show current parameters and the saved kexec command from the last kdump-config load. status Evaluate /sys/kernel/kexec_crash_loaded and print a corresponding message. load Load the kdump kernel. unload Unload the kdump kernel. savecore If /proc/vmcore exists, save it using makedumpfile. FILES
/etc/init.d/kdump-tools init script to automatically load a kdump kernel, or save a vmcore and reboot. /etc/default/kdump-tools configuration file /var/crash/kernel_link a link to the current debug kernel /var/crash/kexec_cmd the last kexec_cmd executed by kdump-config DIAGNOSTICS
USE_KDUMP is not set or zero The variable USE_KDUMP in the file /etc/default/kdump-tools is 0. To use kdump, edit the file and change the value to 1. kdump is not supported by this kernel The file /sys/kernel/kexec_crash_loaded does not exist. This means that the currently running kernel either was not configured to support kdump, or that a crashkernel= commandline parameter was not used when the currently running kernel booted. no crashkernel= parameter in the kernel cmdline a crashkernel= commandline parameter was not used when the currently running kernel booted. You will need to add a crashkernel= parameter to your /etc/lilo.conf, /etc/elilo.conf or grub /boot/grub/menu.lst file and reboot, before kdump will work. See installed READMEs for suggestions. could not find an installed debug vmlinux image and DEBUG_KERNEL is not specified in /etc/default/kdump-tools Warning: makedumpfile will be limited to -d 1. A debug version of the currently booted kernel could not be found. KDUMP_KERNEL does not exist: $KDUMP_KERNEL A KDUMP_KERNEL was specified in /etc/default/kdump-tools, but it cannot be found. KDUMP_INITRD does not exist: $KDUMP_INITRD A KDUMP_INITRD was specified in /etc/default/kdump-tools, but it cannot be found. no KDUMP_KERNEL in $KDUMP_DEFAULTS and can't find a kdump package directory in /usr/lib no kdump kernel could be found. found a linux-kdump package in $KDUMP_PKG_DIR but can't find a kdump kernel in $KDUMP_PKG_DIR this indicates a broken linux-kdump package installation. no kdump initrd image: $KDUMP_INITRD an initrd will not be used this indicates that although a kdump kernel was found, a corresponding initrd was not found. kdump kernel relocation address does not match crashkernel= parameter For non-relocatable architectures, the kdump kernel must be built with a predetermined start address. This message indicates that the start address of the kdump kernel and the start address in the crashkernel= parameter do not match. failed to load kdump kernel kexec reported that it could not load the kdump kernel. failed to unload kdump kernel kexec reported that it could not unload the kdump kernel. Run 'kexec -u' directly for more detail. makedumpfile failed, falling back to 'cp' this message is printed if the kdump-tools init script attempts to save a /proc/vmcore file using makedumpfile and the save fails. failed to save vmcore in $KDUMP_STAMPDIR this message indicates that makedumpfile and the fallback method of using cp has failed. This usually occurs if pathnames are wrong or if the disk is full. SEE ALSO
/usr/share/doc/kdump-tools/README /usr/share/doc/kdump-tools/README.Debian kdump-tools(5), kexec(8), crash(8), gdb(1), makedumpfile(8) AUTHOR
Terry Loftin <terry.loftin@hp.com> kdump-tools v1.1.3 April 2007 kdump-config(8)
