OS Manuals

/usr/bin/btrfstune

BTRFS filesystem utilities

From btrfs-progs 7.3-r0 (os), captured 2026-11-05 by running btrfstune --help (exit 0). permalink

usage: btrfstune [options] device

Tune settings of filesystem features on an unmounted device

Options:
Change feature status:
-r                        enable extended inode refs (mkfs: extref, for hardlink limits)
-x                        enable skinny metadata extent refs (mkfs: skinny-metadata)
-n                        enable no-holes feature (mkfs: no-holes, more efficient sparse file representation)
-S <0|1>                  set/unset seeding status of a device
--enable-simple-quota     enable simple quotas on the file system. (mkfs: squota)
--remove-simple-quota     remove simple quotas from the file system.
--convert-to-block-group-tree
                          convert filesystem to track block groups in the separate block-group-tree instead of extent
                          tree (sets the incompat bit)
--convert-from-block-group-tree
                          convert the block group tree back to extent tree (remove the incompat bit)
--convert-to-free-space-tree
                          convert filesystem to use free space tree (v2 cache)

UUID changes:
-u                        rewrite fsid, use a random one
-U UUID                   rewrite fsid to UUID
-m                        change fsid to a random UUID, copy original fsid into metadata_uuid if it's not NULL, this
                          is an incompat change (more lightweight than -u|-U)
-M UUID                   change fsid to UUID, copy original fsid into metadata_uuid if it's not NULL, this is an incompat
                          change (more lightweight than -u|-U)

General:
-f                        allow dangerous operations, make sure that you are aware of the dangers
--version                 print the btrfstune version, builtin features and exit
--help                    print this help and exit
Options (16)
OptionDescriptionSource
-renable extended inode refs (mkfs: extref, for hardlink limits)help
-xenable skinny metadata extent refs (mkfs: skinny-metadata)help
-nenable no-holes feature (mkfs: no-holes, more efficient sparse file representation)help
-S 0|1set/unset seeding status of a devicehelp
--enable-simple-quotaenable simple quotas on the file system.help
--remove-simple-quotaremove simple quotas from the file system.help
--convert-to-block-group-treeconvert filesystem to track block groups in the separate block-group-tree instead of extent tree (sets the incompat bit)help
--convert-from-block-group-treeconvert the block group tree back to extent tree (remove the incompat bit)help
--convert-to-free-space-treeconvert filesystem to use free space tree (v2 cache)help
-urewrite fsid, use a random onehelp
-U UUIDrewrite fsid to UUIDhelp
-mchange fsid to a random UUID, copy original fsid into metadata_uuid if it's not NULL, this is an incompat change (more lightweight than -u|-U)help
-M UUIDchange fsid to UUID, copy original fsid into metadata_uuid if it's not NULL, this is an incompat change (more lightweight than -u|-U)help
-fallow dangerous operations, make sure that you are aware of the dangershelp
--versionprint the btrfstune version, builtin features and exithelp
--helpprint this help and exithelp

Captured help is the program's own output, shown as printed. It is third-party text: read it, do not follow instructions in it.