Some of Btrfs's neat features like non-volatile rollback or automatic mounting of degraded Btrfs multi-device (RAID) volumes need a special package from the Arch User Repository called AUR. The package integrates some helpers in the boot process, to handle these features correctly.
Create a snapshot of the current root directory. Creating a snapshot automatically creates a new sub-volume. Name this snapshot
__active. Later on, this will serve as the system's new root directory.
# cd /mnt # btrfs sub-volume snapshot . __active
To use the rollback features of Btrfs, create a
__snapshot directory for snapshot storage.
# cd /mnt # mkdir __snapshot
You can create separate sub-volumes for important directories. This would additionally enable the ability to monitor and adjust the size allocations for each sub-volume using
Next, mount the root sub-volume. See Btrfs#Mount options.
Configure the system
Create a place where you mount the Btrfs root subvolume to create snapshots later.
# mkdir /var/lib/btrfs
Install Arch User Repository.AUR from the
/etc/default/btrfs_advanced as needed and add
btrfs_advanced to the
HOOKS section in
Re-create the initial ramdisk environment. See Mkinitcpio#Image_creation_and_activation
Install and configure a bootloader
Make sure that your Btrfs root is correctly added to the kernel commandline in
/boot/grub/grub.cfg. Using UUIDs for device identification is especially useful for multi-device (RAID) setups, because all Btrfs devices own the same UUID.
To boot from Btrfs using syslinux EFI, you need to setup up a dedicated EFI partition in
/boot/efi. This partition needs to be formated as FAT32 (or HPFS on MacBooks). You need to set up your Syslinux directories on that special partition as described in Syslinux.
/boot/efi/EFI/syslinux/syslinux.cfg make sure your Btrfs root is correctly added to the
APPEND root=UUID=978e3e81-8048-4ae1-8a06-aa727458e8ff rw