NAME

       mkfs.btrfs - create a btrfs filesystem

SYNOPSIS

       mkfs.btrfs [ -A alloc-start ] [ -b byte-count ] [ -d data-profile ] [ -f ] [ -n nodesize ]
       [ -l leafsize ] [ -L label ] [ -m metadata profile ] [  -M  mixed  data+metadata  ]  [  -s
       sectorsize ] [ -r rootdir ] [ -K ] [ -O feature1,feature2,... ] [ -h ] [ -V ]
        device [ device ... ]

DESCRIPTION

       mkfs.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 the page size. 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.

       -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 fs.

       -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 run

              mkfs.btrfs -O list-all

       -V, --version
              Print the mkfs.btrfs version and exit.

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

       mkfs.btrfs  is  part  of  btrfs-tools. Btrfs is currently under heavy development, and not
       suitable for any uses other than benchmarking and review.  Please refer to the btrfs  wiki
       http://btrfs.wiki.kernel.org for further details.

SEE ALSO

       btrfsck(8)

                                                                                    MKFS.BTRFS(8)