I trying to setup a Raid 1 using btrfs.
Generally ArchLinuxARM supports single device btrfs without tweaking anything. But adding another device and rebooing results in a boot failure "Device not found".
So I figured out, that using an initrd (or initramfs) solves this, as it can hande btrfs. At Archlinux there is the mkinitcpio tool, which I used:
#/etc/mkinitcpio.conf
MODULES="btrfs"
BINARIES="/usr/bin/btrfsck"
HOOKS="base udev autodetect modconf block btrfs filesystems keyboard fsck"
And the command:
sudo mkinitcpio -g /boot/initrd
Then I added this to /boot/cmdline.txt
initrd=0xa00f00000
And to /boot/config.txt
initramfs initrd 0xa00f00000
But it simply ignoring this and not using initramfs at boot.
I checked this adding break and break=premount in cmdline.txt, which has just an effect, when using initramfs.
So where is my fault?
PS.: ArchLinuxARM linux kernel has initrd support. I checked this.