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
	      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 from
       http://e2fsprogs.sourceforge.net.

SEE ALSO
       mke2fs(8), tune2fs(8)


E2fsprogs version 1.47.3	   July 2025			     E2UNDO(8)