Hi, all -- I have an existing system with a raw-partitioned /dev/sda (128G SSD) that I plan to convert to a mirrored boot drive. I installed /dev/sde (256G SSD) and sliced it the same way (well, with a bigger 4th slice) and set up half mirrors in each partition. I've been waiting for the opportunity to copy the sda partitions over to the new sde mirrors and then swap sda for a new 256G SSD and add the other half of each mirror. So now I have just bought another 10T drive to add into the RAID-5 array (that's a whole separate project, of course), so I shut it all down and not only plugged in the big drive (but did nothing else with it) but also copied over each slice and figured hey, yippee, I'll reboot from the mirror and be another step forward. Then GRUB puked all over itself and I can't get the stupid thing running at all now. I've disconnected /dev/sde, I've disconnected all USB external drives, I've disconnected all internal drives, I've swapped out /dev/sda and put /dev/sde back, and I get that GRUB can't boot from a GPT disk ... except that /dev/sda has always been that! So now I might as well go ahead and install a fresh version into the alt-root slice in order to get GRUB working again and then figure out how to get back to the real-root original. But ... do I slice the disk and create four mirrors or do I mirror the disk and create four partitions therein? I was happy with four mirrors, but then there's the question of whether or not GRUB will work, and I don't really want to have to create another I've-lost-count partitions for /boot and /efi and whatever. I've seen so much advice both ways, much of it from 2011 and 2012, that I don't know which way to go! My goal is to mirror two SSDs and have four swap real-root alt-root data partitions; however I get there so that I can boot from either root works for me. Anyone have the "Simple Setup for Dummy David" instruction set? Thanks in advance! :-D -- David T-G See http://justpickone.org/davidtg/email/ See http://justpickone.org/davidtg/tofu.txt