I think I have fixed this in mdadm_2.5.6-7ubuntu4. Please could you install this, which I have just uploaded, and check if it works.
** Changed in: mdadm (Ubuntu) Assignee: (unassigned) => Ian Jackson Status: Confirmed => Fix Committed -- initramfs script: race condition between sata and md https://launchpad.net/bugs/75681 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs