Following the instructions at Setting Up RAID During 13.04 Install --
I think I have Ubuntu 14 now installed on my "md3" RAID partition.
The main chicken-and-egg problem is that the default Ubuntu 14 Desktop can't do RAID, so after it's installed on a RAID partition, it apparently can't boot.
After installing mdadm, it can handle RAID partitions fine -- but how to install mdadm when the OS won't even boot?
The main steps are:
- Prepare a Ubuntu USB stick and boot from it
- Use the "try Ubuntu" and open a terminal window.
- If you don't already have raw partitions set up, set them up with cfdisk or gparted.
- Install mdadm the first time -- on the USB stick -- with
apt-get install mdadm
- If you don't already have the raw partitions raided together, do that now with
mdadm --create ...
- Start the installer (icon on the LiveUSB desktop)
- Specify partitions manually, and pick the raid partition (in my case,
md3), Use as Ext4, and mount it as "/". (I didn't seem to need a separate "/boot" partition, but that might be a quirk of my particular setup).
- IMPORTANT: On the last screen of the installer, choose "continue testing" (NOT "reboot"). If you race past this and try to boot off the hard drive, it won't work -- boot the LiveUSB image again and continue with the next step.
- While still running on the USB stick, install mdadm the second time -- on the hard drive -- with "chroot" and
apt-get install mdadm (again).
- Copy the first part of the first hard disk to the second one using 'dd' -- the MBR, the GRUB boot loader, and the boot partition.
Honestly, this seems unnecessarily complicated -- I will upvote anyone who posts a simpler answer.