E2IMAGE(E)                                             E2IMAGE(E)



NAME
       e2image - Save critical ext2 filesystem data to a file

SYNOPSIS
       e2image [ -r ] device image-file

DESCRIPTION
       The  e2image program will save critical filesystem data on
       the ext2 filesystem located on device to a file  specified
       by image-file.  The image file may be examined by dumpe2fs
       and debugfs, by using the -i  option  to  those  programs.
       This can be used by an expert in assisting the recovery of
       catastrophically corrupted filesystems.   In  the  future,
       e2fsck  will  be enhanced to be able to use the image file
       to help recover a badly damaged filesystem.

       If image-file is -, then the output  of  e2image  will  be
       sent to standard output.

       The  -r  option  will create a raw image file instead of a
       normal image file.  A raw image file differs from a normal
       image file in two ways.  First, the filesystem metadata is
       placed in the proper position so  that  e2fsck,  dumpe2fs,
       debugfs,  etc.  can be run directly on the raw image file.
       In order to minimize the amount of disk space consumed  by
       a  raw  image  file, the file is created as a sparse file.
       (Beware of copying or compressing/decompressing this  file
       with  utilities that don't understand how to create sparse
       files; the file will become as  large  as  the  filesystem
       itself!)  Secondly, the raw image file also includes indi-
       rect blocks and data blocks, which the current image  file
       does not have, although this may change in the future.

       It  is  a very good idea to periodically (at boot time and
       every week or  so)  to  create  image  files  for  all  of
       filesystems  on  a system, as well as saving the partition
       layout (which can be generated using the  using  fdisk  -l
       command).  Ideally the image file should be stored on some
       filesystem other that the filesystem whose  data  it  con-
       tains,  to  ensure that its data is accessible in the case
       where the filesystem has been badly damaged.

       To save disk space, e2image creates the image  file  as  a
       sparse  file.  Hence, if the image file needs to be copied
       to another location, it should either be compressed  first
       or  copied using the --sparse=always option to GNU version
       of cp.

       The size of an ext2 image file depends  primarily  on  the
       size  of  the  filesystems and how many inodes are in use.
       For a typical 10 gigabyte filesystem, with 200,000  inodes
       in  use  out  of  1.2  million  inodes,  the image file be
       approximately 35 megabytes; a 4 gigabyte  filesystem  with
       15,000  inodes in use out of 550,000 inodes will result in
       a 3 megabyte image file.  Image files  tend  to  be  quite
       compressible;  an  image  file  taking  up 32 megabytes of
       space on disk will generally  compress  down  to  3  or  4
       megabytes.


AUTHOR
       e2image was written by Theodore Ts'o (tytso@mit.edu).

AVAILABILITY
       e2image  is part of the e2fsprogs package and is available
       from anonymous http://e2fsprogs.sourceforge.net.

SEE ALSO
       dumpe2fs(s), debugfs(s)




E2fsprogs version 1.27      March 2002                 E2IMAGE(E)