Section: Maintenance Commands (8)
Updated: March 2020
e2undo - Replay an undo log for an ext2/ext3/ext4 filesystem
will replay the undo log
for an ext2/ext3/ext4 filesystem found on
This can be
used to undo a failed operation by an e2fsprogs program.
will check the filesystem superblock to make sure the undo log matches
with the filesystem on the device. If they do not match,
will refuse to apply the undo log as a safety mechanism. The
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
(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.
was written by Aneesh Kumar K.V. (firstname.lastname@example.org
is part of the e2fsprogs package and is available from