As data partition I have a multi-disk btrfs filesystem. My root disk is ext4
UUID=290624c6-6b95-41fd-94a1-923ebca64b83 / ext4 rw,relatime,data=ordered 0 1 /dev/sdc /mnt/btrfs btrfs rw,relatime,compress-force=zlib,autodefrag 0 0
When I boot the machine, it will wait for 1m30s with the message
A start job is running for dev-sdc.device
And after that
Dependency failed for /mnt/btrfs
When I do log in I can do
mount /mnt/btrfs systemctl default
And it will work. The system will boot normally.
I first though I might need to do something with a mkinitcpio hook, but this page says:
Arch's default mkinitcpio package contains a standard btrfs hook, which is enough to get multi-device (RAID) support. Beside that, the kernel is capable of booting a single-device btrfs root without any hook
So everything should work out of the box.
Why doesn't it work, and what should I do to fix it?