SYNOPSIS
- kdump-config { help | test | show | status | load | unload | savecore | propagate | symlinks {kernel-version} }
DESCRIPTION
kdump-config
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 or /sys/kernel/fadump_register depending on the dump mode and print a corresponding message.
- load
- Load the kdump kernel or register if using firmware assisted dump (fadump)
- unload
- Unload the kdump kernel or unregister if using firmware assisted dump (fadump)
- savecore
- If /proc/vmcore exists, save it using makedumpfile.
- propagate
- Sends public ssh key to remote host for passwordless connection
- symlinks {kernel-version}
-
Verify and create
vmlinuz
and
initrd.img
links in
/var/lib/kdump
according to the provided kernel version. If the target
initrd.img
file is absent, it will create it.
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
- /var/lib/kdump/vmlinuz
- Symbolic link pointing to the current kernel file in /boot
- /var/lib/kdump/initrd.img
- Symbolic link pointing to the initrd.img file with the current kernel version in /boot
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.
- 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.
- Invalid argument : missing kernel version
- The symlinks command was used with a kernel version that is not installed on this server
- Invalid symlink : {symbolic link}
- The listed symbolic link is absent, broken or pointing to the wrong version
- Cannot change symbolic links when kdump is loaded
- The defined symbolic links are already in use. You must unload kdump before using the symlinks command
- Unable to locate kernel hook
- The kdump-tools script responsible for the creation of smaller initrd.img files is absent from /usr/kernel/postinst.d
- Invalid kernel version : {kernel version}
- The kernel version given to the symlinks command does not exist
- fadump is not configured in this kernel.
- The Firmware Assisted Dump (fadump) facility is not available on this platform
- SSH and NFS cannot be defined concurrently
- Both variables are defined in /etc/default/kdump-tools. You must choose one or the other as configuration option.
- Unable to mount remote NFS directory {directory}. Cannot save core
- The remote NFS server does not authorize this server to mount the directory to save the crash dump.
- Unable to write to the remote NFS directory {directory}. Cannot save core
- The remote NFS directory can be mounted but this server cannot write files to it.
- makedumpfile --dump-dmesg failed. dmesg content will be unavailable
- The command to capture the content of the dmesg buffer failed. It will not be available in the crash directory
- Unable to reach remote server {server}. No reason to continue
- kdump-tools is configured for remote dump but the remote server cannot be reached.
- makedumpfile scp failed. The vmcore file will not be available
- The makedumpfile command was successful but the resulting file could not be copied over SSH to the remote server.
- Remote ssh dump is not configured. No reason to propagate
- The propagate command was used but kdump is not configured for remote dump.