How to mount multi-device btrfs filesystem under systemd?

view story

https://bbs.archlinux.org – I am running full, native systemd. It always has an error during boot trying to mount my new, multi-device btrfs filesystem. There was no problem with mounting the filesystem when it resided on a single disk drive.When it fails, it allows me to enter my root password and have a console. In this console, I can successfully mount the btrfs filesystem. Then boot continues normally, and then I can use the filesystem with no further problems, until the next reboot.btrfs filesystem show /dev/sda4 failed to read /dev/sr0 Label: 'TimBTRFS' uuid: 317460bc-5b6a-4dac-acb8-7139dcbcff8b Total d (HowTos)