6 mkfs.btrfs - create a btrfs filesystem
11 $$[-A|--alloc-start <alloc-start>]$$
12 $$[-b|--byte-count <byte-count>]$$
13 $$[-d|--data <data-profile>]$$
15 $$[-n|--nodesize <nodesize>]$$
16 $$[-l|--leafsize <leafsize>]$$
17 $$[-L|--label <label>]$$
18 $$[-m|--metadata <metadata profile>]$$
20 $$[-s|--sectorsize <sectorsize>]$$
21 $$[-r|--rootdir <rootdir>]$$
23 $$[-O|--features <feature1>[,<feature2>...]]$$
24 $$[-U|--uuid <UUID>]$$
27 $$<device> [<device>...]$$
32 is used to create a btrfs filesystem (usually in a disk partition, or an array
36 is the special file corresponding to the device (e.g /dev/sdXX ).
37 If multiple devices are specified, btrfs is created
38 spanning across the specified devices.
42 -A|--alloc-start <offset>::
43 Specify the offset from the start of the device at which to start allocations
44 in this btrfs filesystem. The default value is zero, or the start of the
45 device. This option is intended only for debugging filesystem resize
48 -b|--byte-count <size>::
49 Specify the size of the resultant filesystem. If this option is not used,
50 mkfs.btrfs uses all the available storage for the filesystem.
53 Specify how the data must be spanned across the devices specified. Valid
54 values are 'raid0', 'raid1', 'raid5', 'raid6', 'raid10' or 'single'.
57 Force overwrite when an existing filesystem is detected on the device.
58 By default, mkfs.btrfs will not write to the device if it suspects that
59 there is a filesystem or partition table on the device already.
63 -l|--leafsize <size>::
64 Specify the nodesize, the tree block size in which btrfs stores
65 data. The default value is 16KB (16384) or the page size, whichever is
66 bigger. Must be a multiple of the sectorsize, but not larger than
67 65536. Leafsize always equals nodesize and the options are aliases.
70 Specify a label for the filesystem.
72 NOTE: <name> should be less than 256 characters.
75 -m|--metadata <profile>::
76 Specify how metadata must be spanned across the devices specified. Valid
77 values are 'raid0', 'raid1', 'raid5', 'raid6', 'raid10', 'single' or 'dup'.
80 will have dup set by default except in the case of SSDs which will default to
81 single. This is because SSDs can remap blocks internally so duplicate blocks
82 could end up in the same erase block which negates the benefits of doing
86 Mix data and metadata chunks together for more efficient space
87 utilization. This feature incurs a performance penalty in
88 larger filesystems. It is recommended for use with filesystems
91 -s|--sectorsize <size>::
92 Specify the sectorsize, the minimum data block allocation unit.
95 value is the page size. If the sectorsize differs from the page size, the
96 created filesystem may not be mountable by current kernel. Therefore it is not
97 recommended to use this option unless you are going to mount it on a system
98 with the appropriate page size.
100 -r|--rootdir <rootdir>::
101 Specify a directory to copy into the newly created btrfs filesystem.
103 NOTE: '-r' option is done completely in userland, and don't need root
104 privilege to mount the filesystem.
107 Do not perform whole device TRIM operation by default.
109 -O|--features <feature1>[,<feature2>...]::
110 A list of filesystem features turned on at mkfs time. Not all features are
111 supported by old kernels.
113 To see all features run::::
114 mkfs.btrfs -O list-all
117 Create the filesystem with the specified UUID, which must not already exist on
121 Print the *mkfs.btrfs* version and exit.
128 As default the unit is the byte, however it is possible to append a suffix
129 to the arguments like 'k' for KBytes, 'm' for MBytes...
133 *btrfs* is part of btrfs-progs.
134 Please refer to the btrfs wiki http://btrfs.wiki.kernel.org for