MKFS.BTRFS(8) Btrfs Manual MKFS.BTRFS(8)NAMEmkfs.btrfs - create a btrfs filesystem
SYNOPSISmkfs.btrfs [-A|--alloc-start <alloc-start>] [-b|--byte-count
<byte-count>] [-d|--data <data-profile>] [-f|--force] [-n|--nodesize
<nodesize>] [-l|--leafsize <leafsize>] [-L|--label <label>]
[-m|--metadata <metadata profile>] [-M|--mixed] [-s|--sectorsize
<sectorsize>] [-r|--rootdir <rootdir>] [-K|--nodiscard] [-O|--features
<feature1>[,<feature2>...]] [-h] [-V|--version] <device> [<device>...]
DESCRIPTIONmkfs.btrfs is used to create a btrfs filesystem (usually in a disk
partition, or an array of disk partitions).
<device> is the special file corresponding to the device (e.g /dev/sdXX
). If multiple devices are specified, btrfs is created spanning across
the specified devices.
OPTIONS
-A|--alloc-start <offset>
Specify the offset from the start of the device to start the btrfs
filesystem. The default value is zero, or the start of the device.
-b|--byte-count <size>
Specify the size of the resultant filesystem. If this option is not
used, mkfs.btrfs uses all the available storage for the filesystem.
-d|--data <type>
Specify how the data must be spanned across the devices specified.
Valid values are raid0, raid1, raid5, raid6, raid10 or single.
-f|--force
Force overwrite when an existing filesystem is detected on the
device. By default, mkfs.btrfs will not write to the device if it
suspects that there is a filesystem or partition table on the
device already.
-n|--nodesize <size>
+ -l|--leafsize <size>:: Specify the nodesize, the tree block size in
which btrfs stores data. The default value is 16KB (16384) or the page
size, whichever is bigger. Must be a multiple of the sectorsize, but
not larger than 65536. Leafsize always equals nodesize and the options
are aliases.
-L|--label <name>
Specify a label for the filesystem.
Note
<name> should be less than 256 characters.
-m|--metadata <profile>
Specify how metadata must be spanned across the devices specified.
Valid values are raid0, raid1, raid5, raid6, raid10, single or dup.
Single device will have dup set by default except in the case of
SSDs which will default to single. This is because SSDs can remap
blocks internally so duplicate blocks could end up in the same
erase block which negates the benefits of doing metadata
duplication.
-M|--mixed
Mix data and metadata chunks together for more efficient space
utilization. This feature incurs a performance penalty in larger
filesystems. It is recommended for use with filesystems of 1 GiB or
smaller.
-s|--sectorsize <size>
Specify the sectorsize, the minimum data block allocation unit.
The default value is the page size. If the sectorsize differs from
the page size, the created filesystem may not be mountable by
current kernel. Therefore it is not recommended to use this option
unless you are going to mount it on a system with the appropriate
page size.
-r|--rootdir <rootdir>
Specify a directory to copy into the newly created btrfs
filesystem.
Note
-r option is done completely in userland, and don’t need root
privilege to mount the filesystem.
-K|--nodiscard
Do not perform whole device TRIM operation by default.
-O|--features <feature1>[,<feature2>...]
A list of filesystem features turned on at mkfs time. Not all
features are supported by old kernels.
To see all features run
mkfs.btrfs-O list-all
-V|--version
Print the mkfs.btrfs version and exit.
-h
Print help.
UNIT
As default the unit is the byte, however it is possible to append a
suffix to the arguments like k for KBytes, m for MBytes...
AVAILABILITY
btrfs is part of btrfs-progs. Please refer to the btrfs wiki
http://btrfs.wiki.kernel.org for further details.
SEE ALSObtrfs(8)Btrfs v3.14.2 05/30/2014 MKFS.BTRFS(8)
