DUMPE2FS(8)               (August 2021)               DUMPE2FS(8)

     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 sys-
               tem.  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 dis-
               played 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.

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     DUMPE2FS(8)               (August 2021)               DUMPE2FS(8)

          -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 com-
          pleted 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)

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