My problem turned out to be (probably) unrelated. For some reason dmraid got to the drives before mdadm (which didn't happen in 10.10). Booting with nodmraid solved my problem.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/728435 Title: raid1 boot degraded mode fails -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs