debugreiserfs

debugreiserfs [-f] [-h] [-J] [-j journal_device] [-O objectid] [-R] [-S] [-T] device

-f
    Full dump of superblock contents

-h
    Display usage help message

-J
    Print journal header from device

-j journal_device
    Print journal header from separate journal device

-O objectid
    Print specified objectid header

-R
    Print bitmap block

-S
    Print superblock summary

-T
    Print tree structure (indirect items)

debugreiserfs is a utility from the reiserfsprogs package designed to extract and display detailed information from ReiserFS filesystem structures, primarily the superblock, without mounting the device. ReiserFS, a journaling filesystem optimized for small files and metadata efficiency, was popular in the early 2000s but is now obsolete and unsupported in modern kernels.

This command reads raw data from a block device (e.g., /dev/sda1) and dumps human-readable contents of on-disk structures like the superblock, journal header, bitmaps, object IDs, and indirect items. It is essential for troubleshooting corruption, analyzing filesystem layout during recovery, or forensic analysis. By default, it prints a summary of the superblock, including block counts, journal location, and format version.

Run as root on unmounted devices to avoid risks. Output helps verify integrity before using tools like reiserfsck. Due to ReiserFS deprecation, use is limited to legacy systems; modern alternatives like ext4 or Btrfs have superior tools such as dumpe2fs. Misuse on wrong devices can lead to confusion but is read-only safe.

Read-only but requires root; ReiserFS unsupported in kernels >5.18; avoid on mounted filesystems; legacy only, prefer modern FS.

debugreiserfs /dev/sda1
Prints superblock summary.
debugreiserfs -f -J /dev/sda1
Full superblock and journal.

Part of reiserfsprogs; install via distro repos if available.

Developed by Namesys (Hans Reiser) as part of reiserfsprogs (~2001-2006); last stable release 3.6.27 (2017); abandoned post-2008 due to creator's imprisonment and kernel drop.

reiserfsck(8), mkreiserfs(8), reiserfstune(8), resize_reiserfs(8)