DUMPE2FS(8)

✨ DUMPE2FS(8) ✨

okay bestie, welcome to dumpe2fs — it's a manual page, it lives in the System Manager's Manual, and it's about to tell you everything your ext2/ext3/ext4 file system is hiding from you. 💖

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🌸 NAME 🌸

dumpe2fs — dump ext2/ext3/ext4 file system information 🫶

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🎀 SYNOPSIS 🎀

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

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🦋 DESCRIPTION 🦋

So basically, dumpe2fs prints the super block and the blocks group information for the file system that's sitting on device. That's it. That's the whole job. And it ate. 👑

The device specifier can be any of these three things, and honestly the flexibility is iconic:

• a filename, like /dev/sda1
• a LABEL specifier: "LABEL=volume-label"
• a UUID specifier: "UUID=uuid"

Like, for real for real, either LABEL=home or UUID=e40486c6-84d5-4f2f-b99c-032281799c9d. Pick your fighter. 💅

⚠️ Note, and this one matters: when you use this on a mounted file system, the information it prints may be old or inconsistent. Not me warning you twice. Okay maybe me warning you twice. 😭

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💜 OPTIONS 💜

• -b — prints the blocks that are reserved as bad in the file system. The little shame blocks. We still love them. 🙈
• -o superblock=superblock — use the block superblock when examining the file system. Ngl, you usually do not need this. It's for the file system wizard examining the remains of a very badly corrupted file system. Like, forensic vibes only. 🔥
• -o blocksize=blocksize — use blocks of blocksize bytes when examining the file system. Same deal: not usually needed, except by that same file system wizard doing autopsies on a very badly corrupted file system. 🧚
• -f — force dumpe2fs to display a file system even though it may have some file system feature flags that dumpe2fs may not understand (and which can cause some of dumpe2fs's display to be suspect). Basically "bestie I don't know her but show me anyway." 💀
• -g — display the group descriptor information in a machine readable colon-separated value format. Very demure, very parseable. The fields displayed are, in order:
  1. the group number
  2. the number of the first block in the group
  3. the superblock location (or -1 if not present)
  4. the range of blocks used by the group descriptors (or -1 if not present)
  5. the block bitmap location
  6. the inode bitmap location
  7. 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. Superblock only. Minimalist era. ✨
• -i — display the file system data from an image file created by e2image, using device as the pathname to the image file. Yes, device is the image path here. No, that's not a typo, that's just how she works. 🌈
• -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. And if you use it together with the -i option, only the MMP block information is printed. 🍓
• -x — print the detailed group information block numbers in hexadecimal format. Hex girlies rise. 💅
• -V — print the version number of dumpe2fs and exit. Bye! 👋

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⭐ EXIT CODE ⭐

dumpe2fs exits with a return code of 0 if the operation completed without errors. She'll 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

So if your script goes sideways, that non-zero is your sign. Periodt. 🚨

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💀 BUGS 💀

You may need to know the physical file system structure to understand the output. That's the bug note. That's it. It's giving "read the room and also read the disk layout." 😭

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👑 AUTHOR 👑

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

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🌈 AVAILABILITY 🌈

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

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💖 SEE ALSO 💖

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

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okay that's the whole page, you're so welcome, go dump some file system info and slay 💅✨

sign-off time: this was E2fsprogs version 1.47.4, dated March 2025, and it's the DUMPE2FS(8) page of the System Manager's Manual. mwah. 🎀🦋💜