DUMPE2FS

Section: Maintenance Commands (8)
Updated: December 2021
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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 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.

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.

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8. System administration commands (usually only for root)