NAME

       dumpe2fs - dump ext2/ext3/ext4 file system information

SYNOPSIS

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

DESCRIPTION

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

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

OPTIONS

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

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

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

       -f     force  dumpe2fs  to  display a file system even though it may have some file system
              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 file system 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 file system, 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 file system 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)