List of features (see also `mkfs.btrfs`(8) section 'FILESYSTEM FEATURES'):
-big_metadata::
+*big_metadata*::
(since: 3.4)
+
-the filesystem uses 'nodesize' bigger than the page size
+the filesystem uses 'nodesize' for metadata blocks, this can be bigger than the
+page size
-compress_lzo::
+*compress_lzo*::
(since: 2.6.38)
+
the 'lzo' compression has been used on the filesystem, either as a mount option
or via *btrfs filesystem defrag*.
-default_subvol::
+*default_subvol*::
(since: 2.6.34)
+
the default subvolume has been set on the filesystem
-extended_iref::
+*extended_iref*::
(since: 3.7)
+
increased hardlink limit per file in a directory to 65536, older kernels
supported a varying number of hardlinks depending on the sum of all file name
sizes that can be stored into one metadata block
-mixed_backref::
+*mixed_backref*::
(since: 2.6.31)
+
-the last major disk format change, improved backreferences
+the last major disk format change, improved backreferences, now default
-mixed_groups::
+*mixed_groups*::
(since: 2.6.37)
+
mixed data and metadata block groups, ie. the data and metadata are not
on the other hand, the final layout is quite unpredictable and possibly highly
fragmented, which means worse performance
-no_holes::
+*no_holes*::
(since: 3.14)
++
improved representation of file extents where holes are not explicitly
stored as an extent, saves a few percent of metadata if sparse files are used
-raid56::
+*raid56*::
(since: 3.9)
+
the filesystem contains or contained a raid56 profile of block groups
-+
-skinny_metadata::
+
+*skinny_metadata*::
(since: 3.10)
+
reduced-size metadata for extent references, saves a few percent of metadata
for a given filesystem
* get the supported features (can be also found under '/sys/fs/btrfs/features')
-
-The device is usually created by ..., but can be created manually:
+The device is usually created by a system device node manager (eg. udev), but
+can be created manually:
--------------------
# mknod --mode=600 c 10 234 /dev/btrfs-control
--------------------
-The device is not strictly required but the device scanning will not work and a
-workaround would need to be used to mount a multi-device filesystem. The mount
-option 'device' can trigger the device scanning during mount.
+The control device is not strictly required but the device scanning will not
+work and a workaround would need to be used to mount a multi-device filesystem.
+The mount option 'device' can trigger the device scanning during mount.
SEE ALSO
--------