rpms/kexec-tools
7
0
Fork 0
Code Issues Pull Requests Releases Activity

core_collector doc basic fix

Browse Source 
Update core_collector in kdump.conf[.5]:
1. accept <command> not limited to makedumpfile
2. add notes about default core_collector
3. add notes about flattened vmcore

Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
This commit is contained in:
Dave Young 2012-06-08 11:38:01 +08:00
parent 7a7ecb150b
commit 2aa51e665f
3 changed files with 150 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
kdump.conf
View File

@ -34,14 +34,22 @@
# dumping to. Ignored for raw device dumps.
# If unset, will default to /var/crash.
#
# 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.
# core_collector <command> <options>
# - This allows you to specify the command to copy
# the vmcore. You could use the dump filtering
# program makedumpfile, the default one, 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.
# Default core_collector for raw dump is:
# "makedumpfile -F -c --message-level 1 -d 31".
# Default core_collector for other targets is:
# "makedumpfile -c --message-level 1 -d 31".
# For core_collector format details please refer to
# kexec-kdump-howto.txt or kdump.conf manpage.
#
# extra_bins <binaries | shell scripts>
# - This directive allows you to specify additional
@ -82,7 +90,7 @@
#net user@my.server.com
#sshkey /root/.ssh/kdump_id_rsa
path /var/crash
#core_collector makedumpfile -c
#core_collector makedumpfile -c --message-level 1 -d 31
#extra_bins /usr/bin/lftp
#extra_modules gfs2
#default shell

74
kdump.conf.5
View File

@ -61,14 +61,32 @@ 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 core_collector makedumpfile <options>
.B core_collector <command> <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.
This allows you to specify the command to copy the vmcore.
You could use the dump filtering program makedumpfile, the default one,
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.
.PP
Note 1: About default core collector:
Default core_collector for raw dump is:
"makedumpfile -F -c --message-level 1 -d 31".
Default core_collector for other targets is:
"makedumpfile -c --message-level 1 -d 31".
Even if core_collector option is commented out in kdump.conf, makedumpfile
is default core collector and kdump uses it internally.
If one does not want makedumpfile as default core_collector, then they
need to specify one using core_collector option to change the behavior.
.PP
Note 2: If "makedumpfile -F" is used then you will get a flattened format
vmcore.flat, you will need to use "makedumpfile -R" to rearrange the
dump data from stdard input to a normal dumpfile (readable with analysis
tools).
ie. "makedumpfile -R vmcore < vmcore.flat"
.RE
.B extra_bins <binaries | shell scripts>
@ -103,8 +121,48 @@ Note: kdump uses bash as the default shell.
.RE
.SH EXAMPLES
Here is some examples for core_collector option:
.PP
Core collector command format depends on dump target type. Typically for
filesystem (local/remote), core_collector should accept two arguments.
First one is source file and second one is target file. For ex.
.TP
ex1.
core_collector "cp --sparse=always"
see
Above will effectively be translated to:
cp --sparse=always /proc/vmcore <dest-path>/vmcore
.TP
ex2.
core_collector "makedumpfile -c --message-level 1 -d 31"
Above will effectively be translated to:
makedumpfile -c --message-level 1 -d 31 /proc/vmcore <dest-path>/vmcore
.PP
For dump targets like raw, in general, core collector should expect
one argument (source file) and should output the processed core on standard
output. This standard output will be saved to destination using appropriate
commands.
raw dumps examples:
.TP
ex3.
core_collector "cat"
Above will effectively be translated to.
cat /proc/vmcore | dd of=<target-device>
.TP
ex4.
core_collector "makedumpfile -F -c --message-level 1 -d 31"
Above will effectively be translated to.
makedumpfile -F -c --message-level 1 -d 31 | dd of=<target-device>
.PP
examples for other options please see
.I /etc/kdump.conf
.SH SEE ALSO

78
kexec-kdump-howto.txt
View File

@ -440,18 +440,74 @@ is a dump filtering and compression utility provided with kexec-tools. On
some architectures, it can drastically reduce the size of your vmcore files,
which becomes very useful on systems with large amounts of memory.
A typical setup is 'core_collector makedumpfile -c', but check the output of
'/sbin/makedumpfile --help' for a list of all available options (-i and -g
don't need to be specified, they're automatically taken care of). Note that
use of makedumpfile requires that the kernel-debuginfo package corresponding
with your running kernel be installed.
A typical setup is 'core_collector makedumpfile -F -c --message-level 1 -d 31',
but check the output of '/sbin/makedumpfile --help' for a list of all available
options (-i and -g don't need to be specified, they're automatically taken care
of). Note that use of makedumpfile requires that the kernel-debuginfo package
corresponding with your running kernel be installed.
Also note that makedumpfile is only used from the initramfs. Saving a
core from the initscript in the root filesystem is considered a last ditch
effort, only used when the initramfs has failed to save the core properly.
As such only the cp utiltiy is used in the initscripts. The implication
here is that in order to use makedumpfile as your core collector, you must
specify a dump target in /etc/kdump.conf.
Core collector command format depends on dump target type. Typically for
filesystem (local/remote), core_collector should accept two arguments.
First one is source file and second one is target file. For ex.
ex1.
---
core_collector "cp --sparse=always"
Above will effectively be translated to:
cp --sparse=always /proc/vmcore <dest-path>/vmcore
ex2.
---
core_collector "makedumpfile -c --message-level 1 -d 31"
Above will effectively be translated to:
makedumpfile -c --message-level 1 -d 31 /proc/vmcore <dest-path>/vmcore
For dump targets like raw, in general, core collector should expect
one argument (source file) and should output the processed core on standard
output. This standard output will be saved to destination using appropriate
commands.
raw dumps core_collector examples:
---------
ex3.
---
core_collector "cat"
Above will effectively be translated to.
cat /proc/vmcore | dd of=<target-device>
ex4.
---
core_collector "makedumpfile -F -c --message-level 1 -d 31"
Above will effectively be translated to.
makedumpfile -F -c --message-level 1 -d 31 | dd of=<target-device>
About default core collector
----------------------------
Default core_collector for ssh/raw dump is:
"makedumpfile -F -c --message-level 1 -d 31".
Default core_collector for other targets is:
"makedumpfile -c --message-level 1 -d 31".
Even if core_collector option is commented out in kdump.conf, makedumpfile
is default core collector and kdump uses it internally.
If one does not want makedumpfile as default core_collector, then they
need to specify one using core_collector option to change the behavior.
Note: If "makedumpfile -F" is used then you will get a flattened format
vmcore.flat, you will need to use "makedumpfile -R" to rearrange the
dump data from stdard input to a normal dumpfile (readable with analysis
tools).
For example: "makedumpfile -R vmcore < vmcore.flat"
Caveats: