mkfs.btrfs(8)
Create a Btrfs filesystem on one or more block devices.
Synopsis
mkfs.btrfs [OPTION]... [DEVICE]...Description
mkfs.btrfs creates a new Btrfs filesystem on the specified block devices. Btrfs is a modern copy-on-write (CoW) filesystem with built-in RAID, snapshots, and subvolume support. You can create single-device or multi-device (pooled) filesystems.
All devices must be empty or you must use -f to force creation. The filesystem will be initialized and ready to mount immediately after creation.
Common options
| Flag | What it does |
|---|---|
-f | Force creation; overwrite existing filesystem without confirmation |
-L LABEL | Set filesystem label (max 256 characters) |
-d PROFILE | Data profile: single, dup, raid0, raid1, raid1c3, raid1c4, raid10 (default: dup for single device, raid1 for multiple) |
-m PROFILE | Metadata profile: same options as -d (default: dup or raid1) |
-M PROFILE | Mixed data/metadata profile for small filesystems |
-n SIZE | Specify node size in bytes (default: 16384, must be power of 2) |
-s SIZE | Specify sector size in bytes (default: 4096) |
-U UUID | Set filesystem UUID explicitly (normally auto-generated) |
-K | Keep IO tree (avoid unnecessary data copies during initialization) |
-q | Suppress output to stdout |
Examples
Create a single-device Btrfs filesystem on /dev/sda1
mkfs.btrfs /dev/sda1Create filesystem with label 'mydata'
mkfs.btrfs -L mydata /dev/sdb1Create a 2-device mirrored (RAID1) filesystem across sda1 and sdb1
mkfs.btrfs -d raid1 -m raid1 /dev/sda1 /dev/sdb1Create a 3-device striped (RAID0) filesystem for maximum capacity
mkfs.btrfs -d raid0 /dev/sda1 /dev/sdb1 /dev/sdc1Force creation on /dev/sdc1 (overwrites any existing data) with label 'backup'
mkfs.btrfs -f -L backup /dev/sdc1Create mixed-mode filesystem suitable for small devices with 16KB node size
mkfs.btrfs -M -n 16384 /dev/sdd1