You appear to have stacked a raid1 on top of one disk, and another raid1, which itself is only composed of a single disk. Try not doing that and see if that fixes it.
** Changed in: grub-installer (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1311717 Title: grub-efi package failed to install into /target/ To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub-installer/+bug/1311717/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs