/usr/share/doc/kdump-tools/README.Debian is in kdump-tools 1.5.5-2ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 | The kdump-tools package provides init scripts and configuration files to
use kdump.
It is as automated as can be at this point, but some manual configuration
may still be required.  Specifically:
1. Kernel Configuration
    You must boot a kernel that was configured with:
        CONFIG_KEXEC=y
        CONFIG_CRASH_DUMP=y
    For ia64, you also need:
        CONFIG_SPARSEMEM=y
    For the resulting dump to be useful, you probably also want:
        CONFIG_DEBUG_INFO=y
    If you use CONFIG_DISCONTIG, then you can only use makedumpfile level
    1 (omit zero pages).
2. Kdump Kernel
    You must have a kdump kernel, which is either relocatable or built to
    start at a non-default address (which you must also set in the kernel
    command-line parameter, see below).  Linux on ia64 is always
    relocatable; recent x86, x86_64, and powerpc kernels have an option
    for this:
        CONFIG_RELOCATABLE=y
    If your architecture does not support this option, you must build it
    with a non-default CONFIG_PHYSICAL_START option.
    If your boot kernel is relocatable, kdump-config will use it as the
    kdump kernel.  Otherwise, you will have to provide one.  Once you
    have a relocatable crash kernel, set KDUMP_KERNEL and if necessary
    KDUMP_INITRD in the /etc/default/kdump-tools file.
    The kdump kernel needs to be configured with:
        CONFIG_CRASH_DUMP=y
3. Kernel Command line parameter
    You must boot your kernel with a 'crashkernel=' command line parameter,
    for example:
      crashkernel=128M
    That will reserve 128 MB of memory for the kdump kernel to use in case
    of a crash.  See Documentation/kdump/kdump.txt in the Linux source for
    more advanced crashkernel parameter syntax.
    You may also want to add 'nmi_watchdog=1' on certain systems.
4. Local Configuration
   The /etc/default/kdump-tools file can be modified to reflect your 
   setup, if automatic detection fails, or if you need specific
   architectural settings.
5. Architectural considerations
   A) x86 && PAE && memory > 4 Gigabytes 
      will need to 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.
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