.\" -*- nroff -*-
.\" Copyright 2001 by Theodore Ts'o.  All Rights Reserved.
.\" This file may be copied under the terms of the GNU Public License.
.\" 
.TH E2IMAGE 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
.SH NAME
e2image \- Save critical ext2 filesystem data to a file
.SH SYNOPSIS
.B e2image
.I device
.I image-file
.SH DESCRIPTION
The
.B e2image
program will save critical filesystem data on the ext2 filesystem located on 
display or change the filesystem label on the ext2 filesystem located on
.I device  
to a file specified by 
.IR image-file .
The image file may be examined by 
.B dumpe2fs
and
.BR  debugfs ,
by using the
.B \-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.
.PP
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
.B 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.
.PP
To save disk space, 
.B 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 
.B \--sparse=always
option to GNU version of 
.BR cp .  
.PP
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; a sparse image file taking up 32 megabytes of space on
disk will generally compress down to 3 or 4 megabytes.
.PP
.SH AUTHOR
.B e2image 
was written by Theodore Ts'o (tytso@mit.edu).
.SH AVAILABILITY
.B e2image
is part of the e2fsprogs package and is available from anonymous 
http://e2fsprogs.sourceforge.net.
.SH SEE ALSO
.BR dumpe2fs (8),
.BR debugfs (8)