Btrfs - Cheatsheet

# Create a RAID1 mirror. metadata(-m) and data(-d) are mirrored.
    mkfs.btrfs -L MyMirrorDisks -m raid1 -d raid1 /dev/sda /dev/sdb
 
# Show status.
    btrfs fi show
    btrfs filesystem show
 
# Add label.
    btrfs filesystem label [<device>|<mount_point>] [<newlabel>]
 
# Show RAID profile.
    btrfs filesystem df <mount_point>
 
# Create a filesystem across four drives (metadata mirrored, linear data allocation)
    mkfs.btrfs -d single /dev/sdb /dev/sdc /dev/sdd /dev/sde
 
# Stripe the data without mirroring, metadata are mirrored
    mkfs.btrfs -d raid0 /dev/sdb /dev/sdc
 
# Use raid10 for both data and metadata
    mkfs.btrfs -m raid10 -d raid10 /dev/sdb /dev/sdc /dev/sdd /dev/sde
 
# Don't duplicate metadata on a single drive (default on single SSDs)
    mkfs.btrfs -m single /dev/sdb
 
# Use full capacity of multiple drives with different sizes (metadata mirrored, data not mirrored and not striped)
    mkfs.btrfs -d single /dev/sdb /dev/sdc
 
# Scan all devices
    btrfs device scan
 
# Scan a single device
    btrfs device scan /dev/sdb
 
# How do I create a RAID10 striped mirror in Btrfs?
    mkfs.btrfs -m RAID10 -d RAID10 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1