2 .\" Copyright 2001 by Theodore Ts'o. All Rights Reserved.
3 .\" This file may be copied under the terms of the GNU Public License.
5 .TH E2IMAGE 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
7 e2image \- Save critical ext2 filesystem data to a file
18 program will save critical filesystem data on the ext2 filesystem located on
19 display or change the filesystem label on the ext2 filesystem located on
21 to a file specified by
23 The image file may be examined by
29 option to those programs. This can be used by an expert in assisting
30 the recovery of catastrophically corrupted filesystems. In the future,
31 e2fsck will be enhanced to be able to use the image file to help
32 recover a badly damaged filesystem.
36 option will create a raw image file instead. A raw image file differs
37 from a normal image file in two ways. First, the filesystem metadata is
38 placed in the proper position so that e2fsck, dumpe2fs, debugfs,
39 etc. can be run directly on the raw image file. In order to minimize
40 the amount of disk space consumed by a raw image file, the file is
41 created as a sparse file. (Beware of copying or
42 compressing/decompressing this file with utilities that don't understand
43 how to create sparse files; the file will become as large as the
44 filesystem itself!) Secondly, the raw image file also includes indirect
45 blocks and data blocks, which the current image file does not have ---
46 although this may change in the future.
48 It is a very good idea to periodically (at boot time and
49 every week or so) to create image files for all of
50 filesystems on a system, as well as saving the partition
51 layout (which can be generated using the using
53 command). Ideally the image file should be stored on some filesystem
55 the filesystem whose data it contains, to ensure that its data is
56 accessible in the case where the filesystem has been badly damaged.
60 creates the image file as a sparse file.
61 Hence, if the image file
62 needs to be copied to another location, it should
63 either be compressed first or copied using the
65 option to GNU version of
68 The size of an ext2 image file depends primarily on the size of the
69 filesystems and how many inodes are in use. For a typical 10 gigabyte
70 filesystem, with 200,000 inodes in use out of 1.2 million inodes, the
71 image file be approximately 35 megabytes; a 4 gigabyte filesystem with
72 15,000 inodes in use out of 550,000 inodes will result in a 3 megabyte
73 image file. Image files tend to be quite
74 compressible; an image file taking up 32 megabytes of space on
75 disk will generally compress down to 3 or 4 megabytes.
79 was written by Theodore Ts'o (tytso@mit.edu).
82 is part of the e2fsprogs package and is available from anonymous
83 http://e2fsprogs.sourceforge.net.