btrfs-debug-tree(8)

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 verifictaion 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 thre's no valid BTRFS
           signature found, the result may be completely wrong if the data
           do 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>
       (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

       -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
           verbose mode, print count of returned paths and ioctl() return
           value

   logical-resolve [-Pv] [-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

       -v
           verbose mode, print count of returned paths and all ioctl()
           return values

       -s <bufsize>
           set internal buffer for storing the file names to bufsize,
           default is 4096, maximum 64k

   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,
       for a subvolume itself return it's own tree id (ie. subvol id)

           Note
           The result is undefined for the so-called empty subvolumes
           (identified by inode number 2), but such subvolume does not
           contain any files anyway

   subvolid-resolve <subvolid> <path>
       (needs root privileges)

       resolve the absolute path of a 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.

SEE ALSO

   mkfs.btrfs(8)

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