Ok. I'm going to do my best here to explain what I've done to my system, even through I don't truly understand it myself. I just want to know if the potential solution I'm thinking of is sound.
I have a Dell r710 Media Server in my house. I recently set out to migrate from the crappy Perc i6 raid controller to a combo mergerfs and snapraid. At the same time I just wanted to clean some things up. Change the distro on the server. Integrate a new NAS i bought. A number of things.
So... I installed a fresh Ubuntu Mate 16.04 on the server and partitioned 4 partitions. 1G primary ext4 for /boot, 46G primary btrfs for /, 140G logical btrfs for /home, and the rest for swap.
I made it through the install of emby server, sonarr, jackett, and couchpotato and just about completed my configs. Then in install mergerfs and snapraid. I had everything just about ready to take live but I hadn't actually rebooted yet. I wanted to make sure my fstab was going to mount everything back properly and all my crontabs were going to start executing at their perscribed schedules. Really just a sanity check.
I powered down and powered back up and BOOM. Blank screen. No Grub. Nothing. I plugged in my Ubuntu thumb drive and booted to live just to poke around in my fs to see what's going on and my /dev/sda (/boot) directory was EMPTY! No idea how that happened.
Now I've been tinkering with boot-repair and trying to get everything back up and running and as far as I've been able to get is getting into Grub, past Grub, and now it's booting to Busybox.
I'm just about fed up. I'm wondering if I'd be better off to just rsync my /home and /root (sans-/boot) up to my NAS and then do a clean install. Then restore my rsync back down to overwrite the fresh system except for leaving the fresh /boot directory with all the right content in it. What does everything think? Am I nuts? At this point I'm just trying to save my sanity.