E2UNDO(8)                 (August 2021)                 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 mechanism.

          -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@linux.vnet.ibm.com)

     AVAILABILITY
          e2undo is part of the e2fsprogs package and is available

     Page 1              E2fsprogs version 1.46.4    (printed 5/24/22)

     E2UNDO(8)                 (August 2021)                 E2UNDO(8)

          from http://e2fsprogs.sourceforge.net.

     SEE ALSO
          mke2fs(8), tune2fs(8)

     Page 2              E2fsprogs version 1.46.4    (printed 5/24/22)