Manual: e2undo

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-de‐
	      vice.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 1.47.2				January 2025						   E2UNDO(8)