Manual: dumpe2fs

DUMPE2FS(8)					   System Manager's Manual					 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.

       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 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.

       -m     If  the  mmp  feature  is enabled on the file system, check if device is in use by another node, see e2mmpsta‐
	      tus(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	 re‐
       turn 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  .	It  is	currently  being maintained by Theodore Ts'o
       .

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)

E2fsprogs version 1.47.2				January 2025						 DUMPE2FS(8)