2 .\" Copyright 2008 by Theodore Ts'o. All Rights Reserved.
3 .\" This file may be copied under the terms of the GNU Public License.
5 .TH E2UNDO 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
7 e2undo \- Replay an undo log for an ext2/ext3/ext4 file system
33 will replay the undo log
35 for an ext2/ext3/ext4 file system found on
38 used to undo a failed operation by an e2fsprogs program.
44 will check the file system superblock to make sure the undo log matches
45 with the file system on the device. If they do not match,
47 will refuse to apply the undo log as a safety mechanism. The
49 option disables this safety mechanism.
52 Display a usage message.
55 Dry-run; do not actually write blocks back to the file system.
58 Specify the file system's
60 (in bytes) from the beginning of the device or file.
63 Report which block we're currently replaying.
66 Before overwriting a file system block, write the old contents of the block to
67 an undo file. This undo file can be used with e2undo(8) to restore the old
68 contents of the file system should something go wrong. If the empty string is
69 passed as the undo_file argument, the undo file will be written to a file named
70 e2undo-\fIdevice\fR.e2undo in the directory specified via the
71 \fIE2FSPROGS_UNDO_DIR\fR environment variable.
73 WARNING: The undo file cannot be used to recover from a power or system crash.
76 was written by Aneesh Kumar K.V. (aneesh.kumar@linux.vnet.ibm.com)
79 is part of the e2fsprogs package and is available from
80 http://e2fsprogs.sourceforge.net.