Can you run the following commands when this happens and show the output: cat /proc/mdstat grub-probe -vv /target
** 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/1604136 Title: grub efi could not install while installing ubuntu desktop 16.04LTS 64 bits(machine with mdraid volumes including the EFI partition) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub-installer/+bug/1604136/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs