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kdump.conf

NAME

kdump.conf - configuration file for kdump kernel.

DESCRIPTION

kdump.conf is a configuration file for the kdump kernel crash collection service.

kdump.conf provides post-kexec instructions to the kdump kernel. It is stored in the initrd file managed by the kdump service. If you change this file and do not want to restart before it takes effect, restart the kdump service to rebuild to initrd.

For most configurations, you can simply review the examples provided in the stock /etc/kdump.conf.

NOTE: kdump.conf only affects the behavior of the initramfs. Please read the kdump operational flow section of kexec-kdump-howto.txt in the docs to better understand how this configuration file affects the behavior of kdump.

OPTIONS

raw <partition>

Will dd /proc/vmcore into <partition>.

net <nfs mount>

Will mount fs and copy /proc/vmcore to <mnt>/var/crash/%HOST-%DATE/, supports DNS. Note that a fqdn should be used as the server name in the mount point

net <user@server>

Will scp /proc/vmcore to <user@server>:/var/crash/%HOST-%DATE/, supports DNS. NOTE: make sure user has necessary write permissions on server and that a fqdn is used as the server name

<fs type> <partition>

Will mount -t <fs type> <partition> /mnt and copy /proc/vmcore to /mnt/var/crash/%DATE/. NOTE: <partition> can be a device node, label or uuid.

path <path>

Append path to the filesystem device which you are dumping to. Ignored for raw device dumps. If unset, will default to /var/crash.

disk_timeout <seconds>

Number of seconds to wait for disks to appear in sysfs prior to continuing Normally, the kdump initramfs waits for disks that it has determined it needs to use during the course of saving the vmcore. By default, it pauses indefinately, but in certain cases, it may wait indefinately on disks that either wont ever appear (if a usb drive is removed for instance), or for disks that it actually doesn't need (depending on configuration). This allows the pause to be terminated in those events.

core_collector makedumpfile <options>

This directive allows you to use the dump filtering program makedumpfile to retrieve your core, which on some arches can drastically reduce core file size. See /sbin/makedumpfile --help for a list of options. Note that the -i and -g options are not needed here, as the initrd will automatically be populated with a config file appropriate for the running kernel.

link_delay <seconds>

Some network cards take a long time to initialize, and some spanning tree enabled networks do not transmit user traffic for long periods after a link state changes. This optional parameter defines a wait period after a link is activated in which the initramfs will wait before attempting to transmit user data.

kdump_post <binary | script>

This directive allows you to run a specified executable just after the memory dump process terminates. The exit status from the dump process is fed to the kdump_post executable, which can be used to trigger different actions for success or failure.
Note that scripts written for use with this directive must use the /bin/msh interpreter

kdump_pre <binary | script>

Works just like the kdump_post directive, but instead of running after the dump process, runs immediately before. Exit status of this binary is interpreted as follows:
0 - continue with dump process as usual
non 0 - reboot/halt the system
Note that scripts written for this directive must use the /bin/msh interpreter

extra_bins <binaries | shell scripts>

This directive allows you to specify additional binaries or shell scripts you'd like to include in your kdump initrd. Generally only useful in conjunction with a kdump_post binary or script that relies on other binaries or scripts.

extra_modules <module(s)>

This directive allows you to specify extra kernel modules that you want to be loaded in the kdump initrd, typically used to set up access to non-boot-path dump targets that might otherwise not be accessible in the kdump environment. Multiple modules can be listed, separated by a space, and any dependent modules will automatically be included.

options <module> <option list>

This directive allows you to specify options to apply to modules in the initramfs. This directive overrides options specified in /etc/modprobe.conf

default <reboot | halt | shell>

Action to preform instead of mounting root fs and running init process reboot: If the default action is reboot simply reboot the system (this is what most people will want, as it returns the system to a nominal state). shell: If the default action is shell, then drop to an msh session inside the initramfs from where you can manually preform additional recovery actions. Exiting this shell reboots the system. halt: bring the system to a halt, requiring manual reset NOTE: Since kdump.conf is only used to configure the kdump initramfs specifying a default action without also specifying a dump target will cause the default directive to be ignored. A warning will be issued on service start if this invalid configuration is specified. Also note that if no default action is specified, reboot is implied.

EXAMPLES

see /etc/kdump.conf

SEE ALSO

kexec(8) mkdumprd(8)