# dumpe2fs

## 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._
    
           The _device_ specifier can either be a filename (i.e., /dev/sda1),
           or a LABEL or UUID specifier: "**LABEL=**_volume-label_ " or "**UUID=**_uuid_ ".
           (i.e., LABEL=home or UUID=e40486c6-84d5-4f2f-b99c-032281799c9d).
    
           **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.
    


## AVAILABILITY



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


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