man > E2UNDO(8)

E2UNDO(8)                              System Manager's Manual                             E2UNDO(8)

NAME
       e2undo - Replay an undo log for an ext2/ext3/ext4 file system

SYNOPSIS
       e2undo [ -f ] [ -h ] [ -n ] [ -o offset ] [ -v ] [ -z undo_file ] undo_log device

DESCRIPTION
       e2undo  will  replay the undo log undo_log for an ext2/ext3/ext4 file system found on device.
       This can be used to undo a failed operation by an e2fsprogs program.

OPTIONS
       -f     Normally, e2undo will check the file system superblock  to  make  sure  the  undo  log
              matches  with the file system 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 mech‐
              anism.

       -h     Display a usage message.

       -n     Dry-run; do not actually write blocks back to the file system.

       -o offset
              Specify the file system's offset (in bytes) from the beginning of the device or file.

       -v     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.

AUTHOR
       e2undo was written by Aneesh Kumar K.V. (aneesh.kumar AT linux.com)

AVAILABILITY
       e2undo is part of the  e2fsprogs  package  and  is  available  from  http://e2fsprogs.source‐
       forge.net.

SEE ALSO
       mke2fs(8), tune2fs(8)


E2fsprogs version 1.47.0                    February 2023                                  E2UNDO(8)