E2IMAGE(8)

NAME
e2image - Save critical ext2 filesystem data to a file

SYNOPSIS
e2image device image-file

DESCRIPTION
The 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 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.

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; a sparse 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(8), debugfs(8)