Introduction:
  To shorten the size of the dumpfile and the time of creating the
  dumpfile, makedumpfile copies only the necessary pages for analysis
  to the dumpfile from /proc/vmcore.   You can specify the kind of
  unnecessary pages with dump_level. If you want to shorten the size
  further, enable the compression of the page data.

Download:
    https://sourceforge.net/projects/makedumpfile/

Usage:
  makedumpfile [-c] [-E] [-d dump_level] [-x vmlinux] dump_mem dump_file

Example:
  If you want to exclude pages filled by zero, cache pages, user pages
  and free pages and to enable compression, please execute the following
  command.

  # makedumpfile -c -d 31 -x vmlinux /proc/vmcore dumpfile
