kexec-tools/kdump.conf.5

.TH KDUMP.CONF 5 "07/23/2008" "kexec-tools"

.SH NAME
kdump.conf \- configuration file for kdump kernel.

.SH 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.

.B 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.

.SH OPTIONS

.B raw <partition>
.RS
Will dd /proc/vmcore into <partition>.
.RE

.B net <nfs mount>
.RS
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
.RE

.B net <user@server>
.RS
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
.RE

.B <fs type> <partition>
.RS
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.
.RE

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

.B disk_timeout <seconds>
.RS
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.
.RE

.B core_collector makedumpfile <options> 
.RS
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.
.RE

.B link_delay <seconds> 
.RS
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.
.RE

.B kdump_post <binary | script>
.RS
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.
.PP
Note that scripts written for use with this
directive must use the /bin/msh interpreter
.RE

.B kdump_pre <binary | script>
.RS
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:
.PP
0 - continue with dump process as usual
.PP
non 0 - reboot/halt the system
.PP
Note that scripts written for this directive must use 
the /bin/msh interpreter
.RE

.B extra_bins <binaries | shell scripts>
.RS
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.
.RE

.B extra_modules <module(s)>
.RS
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.
.RE

.B options <module> <option list>
.RS
This directive allows you to specify options to apply to 
modules in the initramfs.  This directive overrides options
specified in /etc/modprobe.conf
.RE

.B default <reboot | halt | shell> 
.RS
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.
.RE

.SH EXAMPLES

see 
.I /etc/kdump.conf

.SH SEE ALSO

kexec(8) mkdumprd(8)