debugreiserfs

debugreiserfs [OPTIONS] device

-s block
    Print superblock information from a specified block, and optionally the tree.

-b block
    Print the content of a specified block.

-c
    Check the internal tree structure for consistency.

-l
    List all blocks in the filesystem.

-d
    Dump the entire filesystem tree.

-t
    Print transaction information from the journal.

-p
    Print information about a path within the filesystem.

-i
    Enter interactive mode for manual inspection and modification.

-r
    Attempt to recover the filesystem tree. Use with extreme caution.

-v
    Enable verbose output.

-u
    Attempt to undelete files. Enter undelete mode.

-y
    Assume 'yes' to all prompts. Extremely dangerous, use only when certain.

-S
    Scan the device for all possible superblocks.

-R
    Operate in read-only mode. Highly recommended for initial diagnostics.

-w
    Write changes to disk. Use with extreme caution as it can cause further data loss.

-F
    Fix checksums in the filesystem.

-j
    Print journal information.

-h
    Display help message and exit.

debugreiserfs is a specialized, low-level utility designed for forensic analysis and data recovery on ReiserFS filesystems. Unlike general-purpose filesystem checkers, it allows direct inspection and manipulation of ReiserFS metadata structures, including superblocks, internal trees, and individual blocks. This capability makes it invaluable for recovering data from severely corrupted ReiserFS partitions where standard tools like reiserfsck might fail. Users can view detailed information about the filesystem's internal state, identify corruption points, and in some cases, attempt to manually repair or extract data. However, due to its powerful, direct access to filesystem structures, using debugreiserfs incorrectly carries a significant risk of further data loss. It requires a deep understanding of ReiserFS internals and should always be used with extreme caution, preferably in read-only mode first, and only after backing up critical data.

Using debugreiserfs carries significant risks. Incorrect usage can lead to irreversible data loss or further corruption of the filesystem. It requires advanced knowledge of ReiserFS internals. Always back up your data before attempting any recovery or modification with this tool. It is not a general-purpose filesystem checker and should only be used when reiserfsck is insufficient or fails to resolve issues.

The primary purpose of debugreiserfs is to facilitate data recovery from severely corrupted ReiserFS filesystems. It provides granular control and insights into the filesystem's internal structures, which is critical when automated recovery tools fail to resolve issues. It allows for manual intervention where automated fixes are not possible.

Before using debugreiserfs, especially in write-enabled modes, it is imperative to create a full backup of the affected disk or partition. Always attempt operations in read-only mode (-R) first to understand the extent of corruption without risking further damage. Incorrect commands can lead to unrecoverable data loss.

debugreiserfs is part of the reiserfsprogs suite, developed primarily by Namesys under the leadership of Hans Reiser, starting in the late 1990s. ReiserFS was one of the first journaling filesystems widely available for Linux, and debugreiserfs was an essential low-level tool for its development and debugging. While ReiserFS's active development slowed significantly after 2006, community efforts continue to maintain the existing tools for users with legacy ReiserFS installations.

reiserfsck(8), mkfs.reiserfs(8), mount(8), fsck(8)