Provided by: kdump-tools_1.5.5-2ubuntu1.6_all bug

NAME

       kdump-tools.conf - configuration file for the kdump-tools init script

SYNOPSIS

       /etc/default/kdump-tools

DESCRIPTION

       kdump-tools  manages  the kdump feature of the Linux kernel.  The /etc/default/kdump-tools
       file contains local configuration settings of kdump.

       This file is sourced into a shell script, so it's format should be consistent  with  shell
       scripting.

OPTIONS

       USE_KDUMP
              Controls  whether  or  not  kdump-tools will take any action.  If not set or 0, the
              kdump-tools init script will not run.

       KDUMP_SYSCTL
              Controls when a panic occurs, using the sysctl(8) interface.   Each  time  a  kdump
              kernel  is  loaded,  “sysctl  -w $KDUMP_SYSCTL” is also executed, thus allowing the
              system adiminstrator to maintain customizable conditions for a kdump.  The contents
              of  this  variable  should  be the “variable=value ...”  portion of the “sysctl -w”
              command.  If not set, “kernel.panic_on_oops=1” will be used.  This feature  can  be
              disabled by setting
              KDUMP_SYSCTL=“ 

              See sysctl(8) for more info.

       KDUMP_KERNEL
              A  full  pathname  to a kdump kernel (the kernel that is kexec'd at crash time in a
              reserved memory area, exposing the old kernel's memory for dumping).  If  not  set,
              kdump-config  will  use  the  boot kernel as the kdump kernel if it is relocatable;
              otherwise you must set KDUMP_KERNEL in order for kdump-tools to work.

       KDUMP_INITRD
              A full pathname to the  kdump  initrd  (if  used).   If  KDUMP_KERNEL  is  set  and
              KDUMP_INITRD  is not set, a warning message will be printed, and an initrd will not
              be used.

       KDUMP_COREDIR
              Full  path  to  a  directory  where  the  vmcore  will  be  saved.   Date   stamped
              subdirectories  are  created  each  time  a  vmcore file is processed.  If not set,
              /var/crash will be used.

       KDUMP_FAIL_CMD
              This variable specifies a command to run if the vmcore save fails.  If not set,  no
              special action is taken.

       MAKEDUMP_ARGS
              Extra  arguments  passed  to makedumpfile(8).  If not set, “-c -d 31” will be used.
              This tells makedumpfile to use compression,  and  reduce  the  corefile  to  in-use
              kernel pages only.  See makedumpfile(8) for details.

       KDUMP_KEXEC_ARGS
              Additional arguments to the kexec command used to load the kdump kernel.

       KDUMP_CMDLINE
              Normally,  the current kernel commandline is obtained from /proc/cmdline.  Set this
              variable to override /proc/cmdline.

       KDUMP_CMDLINE_APPEND
              Additional arguments to append to the command line for the kdump  kernel.   If  not
              set, “irqpoll maxcpus=1 nousb” will be used.

USAGE

       kdump-tools  is  as  automated as can be at this point but there are some prerequisites to
       using it.  Additionally, some manual configuration is still required.

   Manual Configuration
       1.     USE_KDUMP  is  set  to  0  by   default.    To   enable   kdump-tools,   edit   the
              /etc/default/kdump-tools configuration file and set USE_KDUMP=1.

       2.     Kernel  Command  line  parameters  -  the kernel must be booted with a crashkernel=
              command line parameter.  Some example crashkernel parameters:
                  ia64:       crashkernel=384M
                  x86:        crashkernel=128M
                  x86_64:     crashkernel=256M

              Some users may also want  to  add  nmi_watchdog=1  on  certain  systems.   The  nmi
              watchdog will cause the kernel to panic (and kdump) if a system hang is detected.

              The  kernel  command  line  parameter  is  generally  set  in  one  of these files:
              /etc/default/grub, /boot/grub/menu.lst, /etc/elilo.conf, or /etc/lilo.conf.  If the
              command  line  parameter  is  changed, a reboot is required in order for it to take
              effect.

       3.     Architectural considerations

              A)     x86 && PAE && memory > 4  Gigabytes  -  use  KDUMP_KEXEC_ARGS="--elf64-core-
                     headers"

              B)     x86  and  x86_64 - Some systems can take advantage of the nmi watchdog.  Add
                     nmi_watchdog=1 to the boot commandline to turn on  the  watchdog.   The  nmi
                     interrupt will call panic if activated.

              C)     ia64  -  Some  systems  may need KDUMP_KEXEC_ARGS="--noio".  Use this if the
                     system hangs after a panic, but before the kdump kernel begins to boot.

   Prerequisites
       1.     Boot Kernel Configuration - The boot kernel must be configured with  CONFIG_KEXEC=y
              and, if it is also to be used as the kdump kernel, CONFIG_CRASHDUMP=y.

              For  ia64,  only  makedumpfile  level  1  will work if the memory model selected is
              CONFIG_DISCONTIG.  CONFIG_SPARSEMEM is recommended instead.

       2.     Kdump Kernel Configuration - The kdump kernel must  be  relocated  or  relocatable.
              ia64  is  relocatable  by  default, but x86, x86_64, and powerpc must be built with
              CONFIG_RELOCATABLE=y.  Other architectures may require a predermined start location
              via  CONFIG_PHYSICAL_START.   If  the  boot kernel is relocatable, kdump-tools will
              automatically use that kernel.  Otherwise, a relocatable or relocated  kernel  will
              need  to be provided.  The kdump kernel can be specified in the /etc/default/kdump-
              tools file.  Set the  KDUMP_KERNEL  variable  and  if  necessary  the  KDUMP_INITRD
              variable to point to the provided kernel and its initrd.

              The kdump kernel must be configured with: CONFIG_CRASH_DUMP=y

EXAMPLES

       Also panic and kdump on oom:
              KDUMP_SYSCTL="kernel.panic_on_oops=1 vm.panic_on_oom=1"

       Use this option on x86 systems with PAE and more than 4 gig of memory:
              KDUMP_KEXEC_ARGS="--elf64-core-headers"

       This option starts a shell if kdump-tools cannot save the vmcore file:
              KDUMP_FAIL_CMD="/bin/bash; reboot -f"

FILES

       /etc/init.d/kdump-tools  an  init  script  to automatically load a kdump kernel, or save a
                                vmcore and reboot.

       /etc/default/kdump-tools the 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

       See kdump-config(8) for explanations of various error messages.

SEE ALSO

       /usr/share/doc/kdump-tools/README
       /usr/share/doc/kdump-tools/README.Debian
       kdump-config(8), kexec(8), sysctl(8), makedumpfile(8), crash(8), gdb(1),

AUTHOR

       Terry Loftin <terry.loftin@hp.com>