E2IMAGE linux command manual

E2IMAGE(8)                                                         E2IMAGE(8)



NAME
       e2image - Save critical ext2/ext3 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 stan-
       dard 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 indirect 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 contains, 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  anony-
       mous http://e2fsprogs.sourceforge.net.

SEE ALSO
       dumpe2fs(8), debugfs(8)




E2fsprogs version 1.35          February 2004                      E2IMAGE(8)