E2UNDOSection: Maintenance Commands (8)
Updated: March 2018
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NAMEe2undo - Replay an undo log for an ext2/ext3/ext4 filesystem
SYNOPSISe2undo [ -f ] [ -h ] [ -n ] [ -o offset ] [ -v ] [ -z undo_file ] undo_log device
DESCRIPTIONe2undo will replay the undo log undo_log for an ext2/ext3/ext4 filesystem found on device. This can be used to undo a failed operation by an e2fsprogs program.
- Normally, e2undo will check the filesystem superblock to make sure the undo log matches with the filesystem on the device. If they do not match, e2undo will refuse to apply the undo log as a safety mechanism. The -f option disables this safety mechanism.
- Display a usage message.
- Dry-run; do not actually write blocks back to the filesystem.
- -o offset
- Specify the filesystem's offset (in bytes) from the beginning of the device or file.
- Report which block we're currently replaying.
- -z undo_file
Before overwriting a file system block, write the old contents of the block to
an undo file. This undo file can be used with e2undo(8) to restore the old
contents of the file system should something go wrong. If the empty string is
passed as the undo_file argument, the undo file will be written to a file named
e2undo-device.e2undo in the directory specified via the
E2FSPROGS_UNDO_DIR environment variable.
WARNING: The undo file cannot be used to recover from a power or system crash.
AUTHORe2undo was written by Aneesh Kumar K.V. (email@example.com)
AVAILABILITYe2undo is part of the e2fsprogs package and is available from http://e2fsprogs.sourceforge.net.
SEE ALSOmke2fs(8), tune2fs(8)
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