dumpe2fs - Man Page

• Display ext2, ext3 and ext4 filesystem information: dumpe2fs /dev/sdXN
• Display the blocks which are reserved as bad in the filesystem: dumpe2fs -b /dev/sdXN
• Force display filesystem information even with unrecognizable feature flags: dumpe2fs -f /dev/sdXN
• Only display the superblock information and not any of the block group descriptor detail information: dumpe2fs -h /dev/sdXN
• Print the detailed group information block numbers in hexadecimal format: dumpe2fs -x /dev/sdXN

tldr.sh

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

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.

-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.

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.

You may need to know the physical file system structure to understand the output.

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

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

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

badblocks(8), debugfs(8), drbd.conf-8.4(5), drbd.conf-9.0(5), e2freefrag(8), e2fsck(8), e2image(8), e2mmpstatus(8), ext4(5), mke2fs(8), tune2fs(8).