NAME

       dumpe2fs - dump ext2/ext3/ext4 filesystem information

SYNOPSIS

       dumpe2fs [ -bfghixV ] [ -o superblock=superblock ] [ -o blocksize=blocksize ] device

DESCRIPTION

       dumpe2fs prints the super block and blocks group information for the filesystem present on device.

       Note: When used with a mounted filesystem, the printed information may be old or inconsistent.

OPTIONS

       -b     print the blocks which are reserved as bad in the filesystem.

       -o superblock=superblock
              use  the block superblock when examining the filesystem.  This option is not usually needed except
              by a filesystem wizard who is examining the remains of a very badly corrupted filesystem.

       -o blocksize=blocksize
              use blocks of blocksize bytes when examining the filesystem.  This option is  not  usually  needed
              except by a filesystem wizard who is examining the remains of a very badly corrupted filesystem.

       -f     force dumpe2fs to display a filesystem even though it may have some filesystem feature flags which
              dumpe2fs may not understand (and which can cause some of dumpe2fs's display to be suspect).

       -g     display the group descriptor information in a machine readable colon-separated value format.   The
              fields  displayed are the group number; the number of the first block in the group; the superblock
              location (or -1 if not present); the range of blocks used by the group descriptors (or -1  if  not
              present);  the  block  bitmap location; the inode bitmap location; and the range of blocks used by
              the inode table.

       -h     only display the superblock  information  and  not  any  of  the  block  group  descriptor  detail
              information.

       -i     display the filesystem data from an image file created by e2image, using device as the pathname to
              the image file.

       -m     If the mmp feature is enabled on the filesystem, check if device is in use by  another  node,  see
              e2mmpstatus(8)  for  full  details.   If  used  together  with  the  -i option, only the MMP block
              information is printed.

       -x     print the detailed group information block numbers in hexadecimal format

       -V     print the version number of dumpe2fs and exit.

EXIT CODE

       dumpe2fs exits with a return code of 0 if the operation completed without errors.  It will  exit  with  a
       non-zero return code if there are any errors, such as problems reading a valid superblock, bad checksums,
       or if the device is in use by another node and -m is specified.

BUGS

       You may need to know the physical filesystem structure to understand the output.

AUTHOR

       dumpe2fs was written by Remy Card <Remy.Card@linux.org>.  It is currently being  maintained  by  Theodore
       Ts'o <tytso@alum.mit.edu>.

AVAILABILITY

       dumpe2fs is part of the e2fsprogs package and is available from http://e2fsprogs.sourceforge.net.

SEE ALSO

       e2fsck(8), e2mmpstatus(8), mke2fs(8), tune2fs(8).  ext4(5)