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

e2undo was written by Aneesh Kumar K.V. (aneesh.kumar@linux.vnet.ibm.com)

e2undo is part of the e2fsprogs package and is available from http://e2fsprogs.sourceforge.net.

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.

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

-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.

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

       -v     Report which block we're currently replaying.

       -zundo_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.

mke2fs(8), tune2fs(8)

E2fsprogs version 1.47.2                          January 2025                                         E2UNDO(8)

e2undo [ -f ] [ -h ] [ -n ] [ -ooffset ] [ -v ] [ -zundo_file ] undo_logdevice