As per my previous post: -
having added my shiny new Samsung 850 EVO SSD, and got things working nicely, I (perhaps foolishly) deleted the content of the original 3 TB spinning disk ( aka spinning rust ), and rebooted.
Immediately, Ubuntu FAILED to boot, most logically because I'd not actually installed a boot sector on the SSD.
Thankfully, this came to my rescue : -
I was able to boot Beast from the USB drive ( which I'd previously used to install Ubuntu ), and download / run Boot Repair: -
sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repairI took the "Recommended Repair" option, gave it a couple of minutes, and c'est voila.
After a nifty reboot, Ubuntu is nicely booting from the SSD, which is FAST
Did I mention it's fast ? Really really really fast :-)