projects / thirdparty / e2fsprogs.git / blame
| Commit | Line | Data |
|---|---|---|
| 348e43dc TT |
1 | .\" -*- nroff -*- |
| 2 | .\" Copyright 2001 by Theodore Ts'o. All Rights Reserved. | |
| 3 | .\" This file may be copied under the terms of the GNU Public License. | |
| 4 | .\" | |
| 5 | .TH E2IMAGE 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@" | |
| 6 | .SH NAME | |
| 7 | e2image \- Save critical ext2 filesystem data to a file | |
| 8 | .SH SYNOPSIS | |
| 9 | .B e2image | |
| 10 | .I device | |
| 11 | .I image-file | |
| 12 | .SH DESCRIPTION | |
| 0edb4d85 | 13 | The |
| 348e43dc | 14 | .B e2image |
| 0edb4d85 | 15 | program will save critical filesystem data on the ext2 filesystem located on |
| 348e43dc | 16 | display or change the filesystem label on the ext2 filesystem located on |
| 0edb4d85 TT |
17 | .I device |
| 18 | to a file specified by | |
| 19 | .IR image-file . | |
| 20 | The image file may be examined by | |
| 21 | .B dumpe2fs | |
| 22 | and | |
| 23 | .BR debugfs , | |
| 24 | by using the | |
| 25 | .B \-i | |
| 26 | option to those programs. This can be used by an expert in assisting | |
| 27 | the recovery of catastrophically corrupted filesystems. In the future, | |
| 28 | e2fsck will be enhanced to be able to use the image file to help | |
| 29 | recover a badly damaged filesystem. | |
| 30 | .PP | |
| 31 | It is a very good idea to periodically (at boot time and | |
| 32 | every week or so) to create image files for all of | |
| 33 | filesystems on a system, as well as saving the partition | |
| 34 | layout (which can be generated using the using | |
| 35 | .B fdisk -l | |
| 36 | command). Ideally the image file should be stored on some filesystem | |
| 37 | other that | |
| 38 | the filesystem whose data it contains, to ensure that its data is | |
| 39 | accessible in the case where the filesystem has been badly damaged. | |
| 40 | .PP | |
| 41 | To save disk space, | |
| 42 | .B e2image | |
| 43 | creates the image file as a sparse file. | |
| 44 | Hence, if the image file | |
| 45 | needs to be copied to another location, it should | |
| 46 | either be compressed first or copied using the | |
| 47 | .B \--sparse=always | |
| 48 | option to GNU version of | |
| 49 | .BR cp . | |
| 50 | .PP | |
| 51 | The size of an ext2 image file depends primarily on the size of the | |
| 52 | filesystems and how many inodes are in use. For a typical 10 gigabyte | |
| 53 | filesystem, with 200,000 inodes in use out of 1.2 million inodes, the | |
| 54 | image file be approximately 35 megabytes; a 4 gigabyte filesystem with | |
| 55 | 15,000 inodes in use out of 550,000 inodes will result in a 3 megabyte | |
| 56 | image file. Image files tend to be quite | |
| 57 | compressible; a sparse image file taking up 32 megabytes of space on | |
| 58 | disk will generally compress down to 3 or 4 megabytes. | |
| 348e43dc TT |
59 | .PP |
| 60 | .SH AUTHOR | |
| 0edb4d85 | 61 | .B e2image |
| 348e43dc TT |
62 | was written by Theodore Ts'o (tytso@mit.edu). |
| 63 | .SH AVAILABILITY | |
| 64 | .B e2image | |
| 65 | is part of the e2fsprogs package and is available from anonymous | |
| 66 | http://e2fsprogs.sourceforge.net. | |
| 67 | .SH SEE ALSO | |
| 68 | .BR dumpe2fs (8), | |
| 69 | .BR debugfs (8) | |
| 70 |