On my Ubuntu Server 14.04 I have large mdadm RAID6 array, and tiny boot HDD. I want to get rid of that boot HDD, and boot system from USB flash drive.
Although I know it is possible to install Ubuntu on a USB flash drive - I don't want to do it in order to limit writes to USB drive (that's literally asking for reliability troubles on a server).
Is there any guidelines or tutorials or suggestions on how to only move my initial steps (GRUB, initrd image e.t.c) of Ubuntu boot to USB stick, and then have / mounted on this RAID array?
Just to clarify - I don't want to move my whole system partition to USB drive, I only want to move the bare minimum there to limit writes on USB stick.