btrfs-inspect-internal(8) ========================= NAME ---- btrfs-inspect-internal - query various internal information SYNOPSIS -------- *btrfs inspect-internal* 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...]:: (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. + `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 '-i' option) -i :::: specify which mirror to print, valid values are 0, 1 and 2 and the superblock must be present on the device + If there are multiple options specified, only the last one is 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 :::: specify offset to a superblock in a non-standard location at 'bytenr', useful for debugging (disables the '-f' option) *dump-tree* [options] :: (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 :::: print info of the specified block only -t :::: 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: [options="compact"] * 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] :: (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 ] :: (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 :::: set internal buffer for storing the file names to 'bufsize', default is 4096, maximum 64k *min-dev-size* [options] :: (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 :::: specify the device 'id' to query, default is 1 if this option is not used *rootid* :: 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* :: (needs root privileges) + resolve the absolute path of a the subvolume id 'subvolid' 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)