Grub install fails on single boot Mint 17, 3TB RAID1, GPT & EFI

[jeff]

Greetings -

I am trying to install Linux Mint 17.1 onto a new Dell Precision and am getting 
a grub-install failed error from the installer. This is a new single-boot UEFI 
system with 2 blank 3 TB drives. Specifically the error is:

Running grub-install /dev/md127
Unable to install GRUB in /dev/md127
Executing ‘grub-install /dev/md127’ failed
This is a fatal error

Since this is the only error information that I have, I am assuming that it 
could be a result of the raid and partitioning setup that the installer balks 
at when installing Grub2. So I will start by clearly stating what my objective 
is, then my disk setup.

My objective is to have Mint installed onto a software RAID1 system that is 
bootable if either drive failes (or is removed from the system), with minimal 
downtime by just installing a new drive and resyncing the RAID. I want to avoid 
additional steps that involve reinstalling grub or the boot files after the 
failure to make the system bootable again.

A summary of my disk setup steps are as follows.
1. Boot to SystemRescueCD and from a terminal window create a RAID1 array from 
both drives.
root# mdadm --create --verbose /dev/md127 --level=1 --raid-devices=2 /dev/sda 
/dev/sdb

This displays the standard warning about ensuring that your resulting boot 
loader understands md/v1.x metadata. Then defaults to using version 1.2 
metadata. According to the Grub2 manual, Section 1.3, Grub2 can read files 
directly from LVM and RAID devices, therefore version 1.2 should be ok.

2. In GParted, selected the raid device (/dev/md127) and assigned a GPT 
partition to it.

3. Using GParted created 3 partitions on the raid array.
md127p1 /boot/efi 550 MB FAT32 EFI System Partition, boot & esp flags set
md127p2 /boot 550 MB FAT32
md127p3 2.73 TB Lvm2 Physical Volume

If I recall correctly, GParted leaves 1 MB untouched before the first 
partition. Then I left 100 MB unallocated after md127p3.

4. From the terminal window, create the following logical volumes.
root# lvcreate -L 8G -n lv_mintroot vg_jab
root# lvcreate -L 4G -n lv_mintvar vg_jab
root# lvcreate -L 2G -n lv_mintswap vg_jab
root# lvcreate -L 80G -n lv_minthome vg_jab
root# lvcreate -L 1000G -n lv_mintgis vg_jab

Side Note: Mint will be a KVM host that will also run a Win7 guest with a 
couple of additional logical volumes for the Windows guest, hence the naming of 
logical volumes. I use a similar setup on my CentOS 6 KVM Host Server with 
several guests and it makes managing the storage easy and understandable.

5. Eject the SystemRescueCD and reboot to the Linux Mint LiveCD installer. Do 
some housekeeping to get Mint to recognize the raid array.

address@hidden sudo apt-get update
address@hidden sudo apt-get remove dmraid
address@hidden sudo apt-get install mdadm
address@hidden sudo mdadm --examine --scan
 ARRAY /dev/md/127 metadata=1.2 UUID baf72191:8d8bb4e4:6b31b91a:c0efe33e 
name=sysresccd:127
address@hidden sudo mdadm --assemble --scan
 mdadm: /dev/md/127 has been started with 2 drives
address@hidden cat /proc/mdstat
 Personalities : [raid1]
 md127 : active raid1 sda[0] sdb[1]

6. Start the Mint installer and select custom partitioning. The custom 
partitioning dialog correctly recognizes the raid array, all previously 
configured partitions, logical volumes, and boot flags.

7. Select each partition and logical volume established in steps #2 and #3 
above and identify the mount point and assign the appropriate file system. The 
/boot/efi and /boot partitions were formated as shown in step #2 above. The LVM 
logical volumes were formatted as XFS file systems, except swap.

8. In Mint there is a menu list below the custom partitioning to identify and 
select the location for installing the boot loader. The RAID1 device 
(/dev/md127) was selected for installing the boot loader (not an individual 
partition or a single drive).

9. Installation progressed normally until the point of installing grub, which 
resulted in the following error:

Running grub-install /dev/md127
Unable to install GRUB in /dev/md127
Executing ‘grub-install /dev/md127’ failed
This is a fatal error

It is my understanding that Mint17.1 is based on Ubuntu 14.04, which includes 
Grub2. And looking at the documentation for Grub2 includes support for Linux 
software (mdadm) RAID1, EFI, and GPT. So I don't know what I am missing with 
this configuration that causes grub-install to fail. I can provide more 
diagnostic information if necessary, but don't know what may be needed, and I 
am looking here for some expert advice.

I am open to suggestions that are oriented towards my objective of having a 
bootable software RAID1 installation if there is something else I need to 
consider. Thanks for reading my (long) post.

Please cc me directly on any replies, as I am subscribed to the daily digest.
Jeff