switch back to btrfs

config/etc/fstab

@@ -3,5 +3,5 @@
 #
 # <file system> <dir>   <type>  <options>       <dump>  <pass>
 
-/dev/mapper/md0-unlocked / ext4 relatime 0 0
+/dev/mapper/md0-unlocked / btrfs relatime 0 0
-/dev/md1 /boot ext4 relatime 0 0
+/dev/md1 /boot btrfs relatime 0 0

post-debootstrap-installer.sh

@@ -18,7 +18,7 @@ apt-get -y install locales
 
 ### boot
 
-apt-get -y install mdadm cryptsetup systemd systemd-sysv dropbear
+apt-get -y install mdadm cryptsetup systemd systemd-sysv dropbear btrfs-tools
 
 # generate minimal mdadm.conf
 mdadm --examine --scan | perl -pe 's/.*\/dev\/md\/?([0-9]+) .*UUID\=(.+?) .*/ARRAY \/dev\/md$1 UUID=$2/' > /etc/mdadm/mdadm.conf

setup.sh

@@ -22,12 +22,12 @@ unset md0pwd
 chroot=/mnt/md0-unlocked
 
 # root device
-mkfs.ext4 /dev/mapper/md0-unlocked
+mkfs.btrfs /dev/mapper/md0-unlocked
 mkdir /mnt/md0-unlocked
 mount /dev/mapper/md0-unlocked /mnt/md0-unlocked
 
 # boot device
-mkfs.ext4 /dev/md1
+mkfs.btrfs /dev/md1
 mkdir "$chroot/boot"
 mount /dev/md1 "$chroot/boot"