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
+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 '-i' option)
--i <super_mirror>::::
-specify which mirror to print, valid values are 0, 1 and 2 and the superblock must be present on the device
+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 is applies.
+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
+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
+
-The result may be completely wrong if the data do not resemble a superblock.
+-s|--super <bytenr>::::
+(see compatibility note above)
+
--s <bytenr>::::
-specify offset to a superblock in a non-standard location at 'bytenr', useful
-for debugging (disables the '-f' option)
+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*)
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)
+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 subvolume does not contain any files anyway
+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 a the subvolume id 'subvolid'
+resolve the absolute path of the subvolume id 'subvolid'
*tree-stats* [options] <device>::
(needs root privileges)