# btrfs-inspect-internal

## NAME



           btrfs-inspect-internal - query various internal information
    


## SYNOPSIS



           **btrfs inspect-internal** _< subcommand> <args>_
    


## DESCRIPTION



           This command group provides an interface to query internal
           information. The functionality ranges from a simple UI to an ioctl
           or a more complex query that assembles the result from several
           internal structures. The latter usually requires calls to
           privileged ioctls.
    


## SUBCOMMAND



           **dump-super**[options] _< device>_ [device...]
               (replaces the standalone tool **btrfs-show-super**)
    
               Show btrfs superblock information stored on given devices in
               textual form. By default the first superblock is printed, more
               details about all copies or additional backup data can be
               printed.
    
               Besides verification of the filesystem signature, there are no
               other sanity checks. The superblock checksum status is
               reported, the device item and filesystem UUIDs are checked and
               reported.
    
                   **Note**
                   the meaning of option _-s_ has changed in version 4.8 to be
                   consistent with other tools to specify superblock copy
                   rather the offset. The old way still works, but prints a
                   warning. Please update your scripts to use _--bytenr_
                   instead. The option _-i_ has been deprecated.
               **Options**
    
               -f|--full
                   print full superblock information, including the system
                   chunk array and backup roots
    
               -a|--all
                   print information about all present superblock copies
                   (cannot be used together with _-s_ option)
    
               -i _< super>_
                   (deprecated since 4.8, same behaviour as _--super_)
    
               --bytenr _< bytenr>_
                   specify offset to a superblock in a non-standard location
                   at _bytenr_ , useful for debugging (disables the _-f_ option)
    
                   If there are multiple options specified, only the last one
                   applies.
    
               -F|--force
                   attempt to print the superblock even if a valid BTRFS
                   signature is not found; the result may be completely wrong
                   if the data does not resemble a superblock
    
               -s|--super _< bytenr>_
                   (see compatibility note above)
    
                   specify which mirror to print, valid values are 0, 1 and 2
                   and the superblock must be present on the device with a
                   valid signature, can be used together with _--force_
    
           **dump-tree**[options] _< device>_ [device...]
               (replaces the standalone tool **btrfs-debug-tree**)
    
               Dump tree structures from a given device in textual form,
               expand keys to human readable equivalents where possible. This
               is useful for analyzing filesystem state or inconsistencies
               and has a positive educational effect on understanding the
               internal filesystem structure.
    
                   **Note**
                   contains file names, consider that if you’re asked to send
                   the dump for analysis. Does not contain file data.
               **Options**
    
               -e|--extents
                   print only extent-related information: extent and device
                   trees
    
               -d|--device
                   print only device-related information: tree root, chunk
                   and device trees
    
               -r|--roots
                   print only short root node information, ie. the root tree
                   keys
    
               -R|--backups
                   same as --roots plus print backup root info, ie. the
                   backup root keys and the respective tree root block offset
    
               -u|--uuid
                   print only the uuid tree information, empty output if the
                   tree does not exist
    
               -b _< block_num>_
                   print info of the specified block only, can be specified
                   multiple times
    
               --follow
                   use with _-b_ , print all children tree blocks of _< block_num>_
    
               --dfs
                   (default up to 5.2)
    
                   use depth-first search to print trees, the nodes and
                   leaves are intermixed in the output
    
               --bfs
                   (default since 5.3)
    
                   use breadth-first search to print trees, the nodes are
                   printed before all leaves
    
               --hide-names
                   print a placeholder _HIDDEN_ instead of various names,
                   useful for developers to inspect the dump while keeping
                   potentially sensitive information hidden
    
                   This is:
    
                   •   directory entries (files, directories, subvolumes)
    
                   •   default subvolume
    
                   •   extended attributes (name, value)
    
                   •   hardlink names (if stored inside another item or as
                       extended references in standalone items)
    
                           **Note**
                           lengths are not hidden because they can be
                           calculated from the item size anyway.
    
               --csum-headers
                   print b-tree node checksums stored in headers (metadata)
    
               --csum-items
                   print checksums stored in checksum items (data)
    
               --noscan
                   do not automatically scan the system for other devices
                   from the same filesystem, only use the devices provided as
                   the arguments
    
               -t _< tree_id>_
                   print only the tree with the specified ID, where the ID
                   can be numerical or common name in a flexible human
                   readable form
    
                   The tree id name recognition rules:
    
                   •   case does not matter
    
                   •   the C source definition, eg. BTRFS_ROOT_TREE_OBJECTID
    
                   •   short forms without BTRFS_ prefix, without _TREE and
                       _OBJECTID suffix, eg. ROOT_TREE, ROOT
    
                   •   convenience aliases, eg. DEVICE for the DEV tree,
                       CHECKSUM for CSUM
    
                   •   unrecognized ID is an error
    
           **inode-resolve**[-v] _< ino> <path>_
               (needs root privileges)
    
               resolve paths to all files with given inode number _ino_ in a
               given subvolume at _path_ , ie. all hardlinks
    
               **Options**
    
               -v
                   (deprecated) alias for global _-v_ option
    
           **logical-resolve**[-Pvo] [-s _< bufsize>_] _< logical> <path>_
               (needs root privileges)
    
               resolve paths to all files at given _logical_ address in the
               linear filesystem space
    
               **Options**
    
               -P
                   skip the path resolving and print the inodes instead
    
               -o
                   ignore offsets, find all references to an extent instead
                   of a single block. Requires kernel support for the V2
                   ioctl (added in 4.15). The results might need further
                   processing to filter out unwanted extents by the offset
                   that is supposed to be obtained by other means.
    
               -s _< bufsize>_
                   set internal buffer for storing the file names to _bufsize_ ,
                   default is 64k, maximum 16m. Buffer sizes over 64K require
                   kernel support for the V2 ioctl (added in 4.15).
    
               -v
                   (deprecated) alias for global _-v_ option
    
           **min-dev-size**[options] _< path>_
               (needs root privileges)
    
               return the minimum size the device can be shrunk to, without
               performing any resize operation, this may be useful before
               executing the actual resize operation
    
               **Options**
    
               --id _< id>_
                   specify the device _id_ to query, default is 1 if this
                   option is not used
    
           **rootid** _< path>_
               for a given file or directory, return the containing tree root
               id, but for a subvolume itself return its own tree id (ie.
               subvol id)
    
                   **Note**
                   The result is undefined for the so-called empty subvolumes
                   (identified by inode number 2), but such a subvolume does
                   not contain any files anyway
    
           **subvolid-resolve** _< subvolid> <path>_
               (needs root privileges)
    
               resolve the absolute path of the subvolume id _subvolid_
    
           **tree-stats**[options] _< device>_
               (needs root privileges)
    
               Print sizes and statistics of trees.
    
               **Options**
    
               -b
                   Print raw numbers in bytes.
    


## EXIT STATUS



           **btrfs inspect-internal** returns a zero exit status if it succeeds.
           Non zero is returned in case of failure.
    


## AVAILABILITY



           **btrfs** is part of btrfs-progs. Please refer to the btrfs wiki
           **http://btrfs.wiki.kernel.org******for further details.


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