MAKEDUMPFILE(8) 					Linux System Administrator's Manual					   MAKEDUMPFILE(8)

NAME

       makedumpfile - make a small dumpfile of kdump

SYNOPSIS

       makedumpfile    [OPTION] [-x VMLINUX|-i VMCOREINFO] VMCORE DUMPFILE
       makedumpfile -F [OPTION] [-x VMLINUX|-i VMCOREINFO] VMCORE
       makedumpfile   [OPTION] -x VMLINUX --config FILTERCONFIGFILE VMCORE DUMPFILE
       makedumpfile -R DUMPFILE
       makedumpfile --split [OPTION] [-x VMLINUX|-i VMCOREINFO] VMCORE DUMPFILE1 DUMPFILE2 [DUMPFILE3 ..]
       makedumpfile --reassemble DUMPFILE1 DUMPFILE2 [DUMPFILE3 ..] DUMPFILE
       makedumpfile -g VMCOREINFO -x VMLINUX
       makedumpfile -E [--xen-syms XEN-SYMS|--xen-vmcoreinfo VMCOREINFO] VMCORE DUMPFILE
       makedumpfile --dump-dmesg [-x VMLINUX|-i VMCOREINFO] VMCORE LOGFILE
       makedumpfile    [OPTION] -x VMLINUX --diskset=VMCORE1 --diskset=VMCORE2 [--diskset=VMCORE3 ..] DUMPFILE
       makedumpfile -h
       makedumpfile -v

DESCRIPTION

       With  kdump,  the  memory image of the first kernel (called "panicked kernel") can be taken as /proc/vmcore while the second kernel (called
       "kdump kernel" or "capture kernel") is running. This document represents /proc/vmcore as VMCORE. makedumpfile makes  a  small  DUMPFILE	by
       compressing  dump data or by excluding unnecessary pages for analysis, or both. makedumpfile needs the first kernel's debug information, so
       that it can distinguish unnecessary pages by analyzing how the first kernel uses the memory.  The information can be taken from VMLINUX	or
       VMCOREINFO.

       makedumpfile  can  exclude the following types of pages while copying VMCORE to DUMPFILE, and a user can choose which type of pages will be
       excluded.
       - Pages filled with zero
       - Cache pages without private pages
       - All cache pages with private pages
       - User process data pages
       - Free pages

       makedumpfile provides two DUMPFILE formats (the ELF format and the kdump-compressed format). By default, makedumpfile makes a  DUMPFILE	in
       the kdump-compressed format. The kdump-compressed format is readable only with the crash utility, and it can be smaller than the ELF format
       because of the compression support. The ELF format is readable with GDB and the crash utility.  If a user wants to use GDB, DUMPFILE format
       has to be explicitly specified to be the ELF format.

       Apart from the exclusion of unnecessary pages mentioned above, makedumpfile allows user to filter out targeted kernel data. The filter con-
       fig file can be used to specify kernel/module symbols and its members that need to be filtered out through the erase command syntax.  make-
       dumpfile  reads	the filter config and builds the list of memory addresses and its sizes after processing filter commands. The memory loca-
       tions that require to be filtered out are then poisoned with character 'X' (58 in Hex). Refer to makedumpfile.conf(5) for file format.

       To analyze the first kernel's memory usage, makedumpfile can refer to VMCOREINFO instead of VMLINUX. VMCOREINFO contains the first kernel's
       information (structure size, field offset, etc.), and VMCOREINFO is small enough to be included into the second kernel's initrd.
       If  the second kernel is running on its initrd without mounting a root file system, makedumpfile cannot refer to VMLINUX because the second
       kernel's initrd cannot include a large file like VMLINUX. To solve the problem, makedumpfile makes VMCOREINFO beforehand, and it refers	to
       VMCOREINFO instead of VMLINUX while the second kernel is running.
       VMCORE has contained VMCOREINFO since linux-2.6.24, and a user does not need to specify neither -x nor -i option.

       If  the	second kernel is running on its initrd without mounting any file system, a user needs to transport the dump data to a remote host.
       To transport the dump data by SSH, makedumpfile outputs the dump data in the intermediate format (the flattened	format)  to  the  standard
       output.	By  piping  the  output  data to SSH, a user can transport the dump data to a remote host. Note that analysis tools (crash utility
       before version 5.1.2 or GDB) cannot read the flattened format directly, so on a remote host the received data in the flattened format needs
       to be rearranged to a readable DUMPFILE format by makedumpfile (or makedumpfile-R.pl).

       makedumpfile  can  read	a  DUMPFILE in the kdump-compressed format instead of VMCORE and re-filter it. This feature is useful in situation
       that users need to reduce the file size of DUMPFILE for sending it somewhere by ftp/scp/etc. (If all of the page types, which are specified
       by a new dump_level, are excluded from an original DUMPFILE already, a new DUMPFILE is the same as an original DUMPFILE.)
       For example, makedumpfile can create a DUMPFILE of dump_level 31 from the one of dump_level 3 like the following:
       Example:
       # makedumpfile -c -d 3 /proc/vmcore dumpfile.1
       # makedumpfile -c -d 31 dumpfile.1 dumpfile.2

       makedumpfile  can read VMCORE(s) in three kinds of sadump formats: single partition format, diskset format and media backup format, and can
       convert each of them into kdump-compressed format with filtering and compression processing. Note that for VMCORE(s) created by sadump, you
       always  need  to  pass  VMLINUX	with -x option. Also, to pass multiple VMCOREs created on diskset configuration, you need to use --diskset
       option.

OPTIONS

       -c     Compress dump data by each page.
	      A user cannot specify this option with -E option, because the ELF format does not support compressed data.
	      Example:
	      # makedumpfile -c -d 31 -x vmlinux /proc/vmcore dumpfile

       -d dump_level
	      Specify the type of unnecessary page for analysis.
	      Pages of the specified type are not copied to DUMPFILE. The page type marked in the following table is excluded. A user can  specify
	      multiple page types by setting the sum of each page type for dump_level. The maximum of dump_level is 31. Note that a dump_level for
	      Xen dump filtering is 0 or 1 on a machine other than x86_64 (On an x86_64 machine, it is possible  to  specify  2  or  bigger  as  a
	      dump_level).
	      If  specifying  multiple	dump_levels with the delimiter ',', makedumpfile retries to create a DUMPFILE by other dump_level when "No
	      space on device" error happens. For example, if dump_level is "11,31" and makedumpfile fails by dump_level 11, makedumpfile  retries
	      it by dump_level 31.
	      Example:
	      # makedumpfile -d 11 -x vmlinux /proc/vmcore dumpfile
	      # makedumpfile -d 11,31 -x vmlinux /proc/vmcore dumpfile

		     |	    |cache  |cache  |	   |
		dump | zero |without|with   | user | free
	       level | page |private|private| data | page
	      -------+------+-------+-------+------+------
		   0 |	    |	    |	    |	   |
		   1 |	X   |	    |	    |	   |
		   2 |	    |	X   |	    |	   |
		   3 |	X   |	X   |	    |	   |
		   4 |	    |	X   |	X   |	   |
		   5 |	X   |	X   |	X   |	   |
		   6 |	    |	X   |	X   |	   |
		   7 |	X   |	X   |	X   |	   |
		   8 |	    |	    |	    |  X   |
		   9 |	X   |	    |	    |  X   |
		  10 |	    |	X   |	    |  X   |
		  11 |	X   |	X   |	    |  X   |
		  12 |	    |	X   |	X   |  X   |
		  13 |	X   |	X   |	X   |  X   |
		  14 |	    |	X   |	X   |  X   |
		  15 |	X   |	X   |	X   |  X   |
		  16 |	    |	    |	    |	   |  X
		  17 |	X   |	    |	    |	   |  X
		  18 |	    |	X   |	    |	   |  X
		  19 |	X   |	X   |	    |	   |  X
		  20 |	    |	X   |	X   |	   |  X
		  21 |	X   |	X   |	X   |	   |  X
		  22 |	    |	X   |	X   |	   |  X
		  23 |	X   |	X   |	X   |	   |  X
		  24 |	    |	    |	    |  X   |  X
		  25 |	X   |	    |	    |  X   |  X
		  26 |	    |	X   |	    |  X   |  X
		  27 |	X   |	X   |	    |  X   |  X
		  28 |	    |	X   |	X   |  X   |  X
		  29 |	X   |	X   |	X   |  X   |  X
		  30 |	    |	X   |	X   |  X   |  X
		  31 |	X   |	X   |	X   |  X   |  X

       -E     Create DUMPFILE in the ELF format.
	      This option cannot be specified with -c option, because the ELF format does not support compressed data.
	      Example:
	      # makedumpfile -E -d 31 -x vmlinux /proc/vmcore dumpfile

       -f     Force existing DUMPFILE to be overwritten.
	      Example:
	      # makedumpfile -f -d 31 -x vmlinux /proc/vmcore dumpfile
	      This command overwrites DUMPFILE even if it already exists.

       -x VMLINUX
	      Specify the first kernel's VMLINUX with debug information to analyze the first kernel's memory usage.
	      This option is necessary if VMCORE does not contain VMCOREINFO, [-i VMCOREINFO] is not specified, and dump_level is 2 or more.
	      The page size of the first kernel and the second kernel should match.
	      Example:
	      # makedumpfile -d 31 -x vmlinux /proc/vmcore dumpfile

       -i VMCOREINFO
	      Specify VMCOREINFO instead of VMLINUX for analyzing the first kernel's memory usage.
	      VMCOREINFO should be made beforehand by makedumpfile with -g option, and it contains the first kernel's information.
	      This option is necessary if VMCORE does not contain VMCOREINFO, [-x VMLINUX] is not specified, and dump_level is 2 or more.
	      Example:
	      # makedumpfile -d 31 -i vmcoreinfo /proc/vmcore dumpfile

       -g VMCOREINFO
	      Generate VMCOREINFO from the first kernel's VMLINUX with debug information.
	      VMCOREINFO must be generated on the system that is running the first kernel. With -i option, a user can specify VMCOREINFO generated
	      on the other system that is running the same first kernel. [-x VMLINUX] must be specified.
	      Example:
	      # makedumpfile -g vmcoreinfo -x vmlinux

       --config FILTERCONFIGFILE
	      Used in conjunction with -x VMLINUX option, to specify the filter config file FILTERCONFIGFILE that contains erase commands to  fil-
	      ter out desired kernel data from vmcore while creating DUMPFILE. For filter command syntax please refer to makedumpfile.conf(5).

       -F     Output the dump data in the flattened format to the standard output for transporting the dump data by SSH.
	      Analysis tools (crash utility before version 5.1.2 or GDB) cannot read the flattened format directly. For analysis, the dump data in
	      the flattened format should be rearranged to a normal DUMPFILE (readable with analysis tools) by -R option. By which option is spec-
	      ified with -F option, the format of the rearranged DUMPFILE is fixed.  In other words, it is impossible to specify the DUMPFILE for-
	      mat when the dump data is rearranged with -R option. If specifying -E option with -F option, the format of the  rearranged  DUMPFILE
	      is  the  ELF format. Otherwise, it is the kdump-compressed format. All the messages are output to standard error output by -F option
	      because standard output is used for the dump data.
	      Example:
	      # makedumpfile -F -c -d 31 -x vmlinux /proc/vmcore 
	      | ssh user@host "cat > dumpfile.tmp"
	      # makedumpfile -F -c -d 31 -x vmlinux /proc/vmcore 
	      | ssh user@host "makedumpfile -R dumpfile"
	      # makedumpfile -F -E -d 31 -i vmcoreinfo	/proc/vmcore 
	      | ssh user@host "makedumpfile -R dumpfile"
	      # makedumpfile -F -E --xen-vmcoreinfo VMCOREINFO /proc/vmcore 
	      | ssh user@host "makedumpfile -R dumpfile"

       -R     Rearrange the dump data in the flattened format from the standard input to a normal DUMPFILE (readable with analysis tools).
	      Example:
	      # makedumpfile -R dumpfile < dumpfile.tmp
	      # makedumpfile -F -d 31 -x vmlinux /proc/vmcore 
	      | ssh user@host "makedumpfile -R dumpfile"

	      Instead of using -R option, a perl script "makedumpfile-R.pl" rearranges the dump data in the flattened format to a normal DUMPFILE,
	      too. The perl script does not depend on architecture, and most systems have perl command.  Even if a remote host does not have make-
	      dumpfile, it is possible to rearrange the dump data in the flattened format to a readable DUMPFILE on a remote host by running  this
	      script.
	      Example:
	      # makedumpfile -F -d 31 -x vmlinux /proc/vmcore 
	      | ssh user@host "makedumpfile-R.pl dumpfile"

       --split
	      Split  the dump data to multiple DUMPFILEs in parallel. If specifying DUMPFILEs on different storage devices, a device can share I/O
	      load with other devices and it reduces time for saving the dump data. The file size of each DUMPFILE is smaller than the system mem-
	      ory size which is divided by the number of DUMPFILEs. This feature supports only the kdump-compressed format.
	      Example:
	      # makedumpfile --split -d 31 -x vmlinux /proc/vmcore dumpfile1 dumpfile2

       --reassemble
	      Reassemble  multiple DUMPFILEs, which are created by --split option, into one DUMPFILE. dumpfile1 and dumpfile2 are reassembled into
	      dumpfile on the following example.
	      Example:
	      # makedumpfile --reassemble dumpfile1 dumpfile2 dumpfile

       --xen-syms XEN-SYMS
	      Specify the XEN-SYMS with debug information to analyze the xen's memory usage.  This option extracts the part of xen  and  domain-0.
	      -E option must be specified with this option.
	      Example:
	      # makedumpfile -E --xen-syms xen-syms /proc/vmcore dumpfile

       --xen-vmcoreinfo VMCOREINFO
	      Specify VMCOREINFO instead of XEN-SYMS for analyzing the xen's memory usage.
	      VMCOREINFO should be made beforehand by makedumpfile with -g option, and it contains the xen's information.  -E option must be spec-
	      ified with this option.
	      Example:
	      # makedumpfile -E --xen-vmcoreinfo VMCOREINFO /proc/vmcore dumpfile

       -X     Exclude all the user domain pages from Xen kdump's VMCORE, and extracts the part of xen and domain-0. If VMCORE contains	VMCOREINFO
	      for Xen, it is not necessary to specify --xen-syms and --xen-vmcoreinfo.	-E option must be specified with this option.
	      Example:
	      # makedumpfile -E -X /proc/vmcore dumpfile

       --xen_phys_start xen_phys_start_address
	      This option is only for x86_64.  Specify the xen_phys_start_address, if the xen code/data is relocatable and VMCORE does not contain
	      xen_phys_start_address in the CRASHINFO.	xen_phys_start_address can be taken from  the  line  of  "Hypervisor  code  and  data"	in
	      /proc/iomem. For example, specify 0xcee00000 as xen_phys_start_address if /proc/iomem is the following:
		-------------------------------------------------------
		# cat /proc/iomem
		...
		  cee00000-cfd99999 : Hypervisor code and data
		...
		-------------------------------------------------------

	      Example:
	      # makedumpfile -E -X --xen_phys_start 0xcee00000 /proc/vmcore dumpfile

       --message-level message_level
	      Specify the message types.
	      Users  can restrict outputs printed by specifying message_level with this option. The message type marked with an X in the following
	      table is printed. For example, according to the table, specifying 7 as message_level means progress indicator, common  message,  and
	      error message are printed, and this is a default value. Note that the maximum value of message_level is 31.

	       message | progress | common  | error   | debug	| report
	       level   | indicator| message | message | message | message
	      ---------+----------+---------+---------+---------+---------
		     0 |	  |	    |	      | 	|
		     1 |    X	  |	    |	      | 	|
		     2 |	  |    X    |	      | 	|
		     3 |    X	  |    X    |	      | 	|
		     4 |	  |	    |	 X    | 	|
		     5 |    X	  |	    |	 X    | 	|
		     6 |	  |    X    |	 X    | 	|
		   * 7 |    X	  |    X    |	 X    | 	|
		     8 |	  |	    |	      |    X	|
		     9 |    X	  |	    |	      |    X	|
		    10 |	  |    X    |	      |    X	|
		    11 |    X	  |    X    |	      |    X	|
		    12 |	  |	    |	 X    |    X	|
		    13 |    X	  |	    |	 X    |    X	|
		    14 |	  |    X    |	 X    |    X	|
		    15 |    X	  |    X    |	 X    |    X	|
		    16 |	  |	    |	      | 	|    X
		    17 |    X	  |	    |	      | 	|    X
		    18 |	  |    X    |	      | 	|    X
		    19 |    X	  |    X    |	      | 	|    X
		    20 |	  |	    |	 X    | 	|    X
		    21 |    X	  |	    |	 X    | 	|    X
		    22 |	  |    X    |	 X    | 	|    X
		    23 |    X	  |    X    |	 X    | 	|    X
		    24 |	  |	    |	      |    X	|    X
		    25 |    X	  |	    |	      |    X	|    X
		    26 |	  |    X    |	      |    X	|    X
		    27 |    X	  |    X    |	      |    X	|    X
		    28 |	  |	    |	 X    |    X	|    X
		    29 |    X	  |	    |	 X    |    X	|    X
		    30 |	  |    X    |	 X    |    X	|    X
		    31 |    X	  |    X    |	 X    |    X	|    X

       --vtop virtual_address
	      This  option  is	useful,  when  user  debugs the translation problem of virtual address. If specifing virtual_address, its physical
	      address is printed. It makes debugging easy by comparing the output of this option with the one of "vtop" subcommand  of	the  crash
	      utility.	"--vtop" option only prints the translation output, and it does not affect the dumpfile creation.

       --dump-dmesg
	      This  option  overrides  the  normal behavior of makedumpfile.  Instead of compressing and filtering a VMCORE to make it smaller, it
	      simply extracts the dmesg log from a VMCORE and writes it to the specified LOGFILE. If a VMCORE  does  not  contain  VMCOREINFO  for
	      dmesg, it is necessary to specfiy [-x VMLINUX] or [-i VMCOREINFO].

	      Example:
	      # makedumpfile --dump-dmesg /proc/vmcore dmesgfile
	      # makedumpfile --dump-dmesg -x vmlinux /proc/vmcore dmesgfile

       --diskset=VMCORE
	      Specify  multiple  VMCOREs  created  on sadump diskset configuration the same number of times as the number of VMCOREs in increasing
	      order from left to right.  VMCOREs are assembled into a single DUMPFILE.

	      Example:
	      # makedumpfile -x vmlinux --diskset=vmcore1 --diskset=vmcore2 dumpfile

       -D     Print debugging message.

       -h     Show help message.

       -v     Show the version of makedumpfile.

ENVIRONMENT VARIABLES

       TMPDIR  This environment variable is for a temporary memory bitmap file.  If your machine has a lots of memory and you use tmpfs  on  /tmp,
	       makedumpfile can fail for a little memory in the 2nd kernel because makedumpfile makes a very large temporary memory bitmap file in
	       this case. To avoid this failure, you can set a TMPDIR environment variable. If you do not set a TMPDIR environment variable, make-
	       dumpfile uses /tmp directory for a temporary bitmap file as a default.

DIAGNOSTICS

       makedumpfile exits with the following value.

       0 : makedumpfile succeeded.

       1 : makedumpfile failed without the following reasons.

       2 : makedumpfile failed due to the different version between  VMLINUX and VMCORE.

       3 : makedumpfile failed due to the analysis error of the memory.

AUTHORS

       Written by Masaki Tachibana, and Ken'ichi Ohmichi.

SEE ALSO

       crash(8), gdb(1), kexec(8), makedumpfile.conf(5)

makedumpfile v1.4.3						 29 February 2012						   MAKEDUMPFILE(8)