Dump ext2/ext3/ext4 filesystem information
dumpe2fs [ -bfhixV ] [ -o superblock=superblock ] [ -o blocksize=blocksize ] device
dumpe2fs prints the super block and blocks group information for the filesystem present on device.
Note: When used with a mounted filesystem, the printed information may be old or inconsistent.
print the blocks which are reserved as bad in the filesystem.
use the block superblock when examining the filesystem. This option is not usually needed except by a filesystem wizard who is examining the remains of a very badly corrupted filesystem.
use blocks of blocksize bytes when examining the filesystem. This option is not usually needed except by a filesystem wizard who is examining the remains of a very badly corrupted filesystem.
force dumpe2fs to display a filesystem even though it may have some filesystem feature flags which dumpe2fs may not understand (and which can cause some of dumpe2fs's display to be suspect).
only display the superblock information and not any of the block group descriptor detail information.
display the filesystem data from an image file created by e2image, using device as the pathname to the image file.
print the detailed group information block numbers in hexadecimal format
print the version number of dumpe2fs and exit.
You need to know the physical filesystem structure to understand the output.
dumpe2fs is part of the e2fsprogs package and is available from http://e2fsprogs.sourceforge.net.