grub2-efi-x64-2.02-100.fc31.x86_64 kernel-5.3.13-300.fc31.x86_64 I've seen this before, so it isn't a regression in either of the above versions. But I'm also not certain when the regression occurred, because the last time I tested Btrfs multiple devices (specifically data single profile), was years ago and I didn't run into this. The gist to reproduce: 1. btrfs single device, single profile data, single profile metadata 2. device starts to run out of space; no problem 'btrfs device add /dev/' voila it works, reboots, keeps on working for a while, but then... 3. install a kernel or two or three or four I suspect that at some point kernels end up on the newly added device due to new block groups eventually being created there, and GRUB subsequently gets confused, starts spewing a bunch of error information which I have to page through. Eventually it does find everything and does boot. But it's kinda ugly and I'm not really sure how to gather more information. Shaky cam video of the boot is here: https://photos.app.goo.gl/wvJbB6kBEFzNwogo6 -- Chris Murphy
