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MEMDUMP(1)		    General Commands Manual		    MEMDUMP(1)

NAME
       memdump - memory	dumper

SYNOPSIS
       memdump	[-kv]  [-b  buffer_size]  [-d  dump_size]  [-m	map_file]  [-p
       page_size]

DESCRIPTION
       This program dumps system memory	to the standard	output	stream,	 skip-
       ping over holes in memory maps.	By default, the	program	dumps the con-
       tents of	physical memory	(/dev/mem).

       Output is in the	form of	a raw dump; if necessary, use the -m option to
       capture memory layout information.

       Output  should be sent off-host over the	network, to avoid changing all
       the memory in the file system cache. Use	netcat,	stunnel,  or  openssl,
       depending on your requirements.

       The  size arguments below understand the	k (kilo) m (mega) and g	(giga)
       suffixes. Suffixes are case insensitive.

       Options

       -k     Attempt to dump kernel memory (/dev/kmem)	rather	than  physical
	      memory.

	      Warning:	this can lock up the system to the point that you have
	      to use the power	switch	(for  example,	Solaris	 8  on	64-bit
	      SPARC).

	      Warning: this produces bogus results on Linux 2.2	kernels.

	      Warning: this is very slow on 64-bit machines because the	entire
	      memory address range has to be searched.

	      Warning: kernel virtual memory mappings change  frequently.  De-
	      pending on the operating system, mappings	smaller	than page_size
	      or buffer_size may be missed or may be reported incorrectly.

       -b buffer_size (default:	0)
	      Number of	bytes per memory read operation. By default, the  pro-
	      gram uses	the page_size value.

	      Warning: a too large read	buffer size causes memory to be	missed
	      on FreeBSD or Solaris.

       -d dump-size (default: 0)
	      Number of	memory bytes to	dump. By default, the program runs un-
	      til  the	memory device reports an end-of-file (Linux), or until
	      it has dumped from /dev/mem as much memory as  reported  present
	      by  the  kernel (FreeBSD,	Solaris), or until pointer wrap-around
	      happens.

	      Warning: a too large value causes	the program to spend a lot  of
	      time skipping over non-existent memory on	Solaris	systems.

	      Warning:	a too large value causes the program to	copy non-exis-
	      tent data	on FreeBSD systems.

       -m map_file
	      Write the	memory map to map_file,	one entry per  line.   Specify
	      -m-  to write to the standard error stream.  Each	map entry con-
	      sists of a region	start address and  the	first  address	beyond
	      that  region.  Addresses are separated by	space, and are printed
	      as hexadecimal numbers (0xhhhh).

       -p page_size (default: 0)
	      Use page_size as the memory page size. By	 default  the  program
	      uses the system page size.

	      Warning:	a too large page size causes memory to be missed while
	      skipping over holes in memory.

       -v     Enable verbose logging for debugging purposes. Multiple  -v  op-
	      tions make the program more verbose.

BUGS
       On  many	hardware platforms the firmware	(boot PROM, BIOS, etc.)	 takes
       away some memory. This memory is	not accessible through /dev/mem.

       This program should produce output in a format that supports  structure
       information such	as ELF.

LICENSE
       This software is	distributed under the IBM Public License.

AUTHOR
       Wietse Venema
       IBM T.J.	Watson Research
       P.O. Box	704
       USA

								    MEMDUMP(1)

NAME | SYNOPSIS | DESCRIPTION | BUGS | LICENSE | AUTHOR

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