I must admit, this discussion is going (technical) places I don't know anything about, and much as I enjoy learning things, I'd rather not waste your time (go make btrfs better! :-p). When all is said and done I'm just a user. I still don't understand how (barring creatively defective hardware, which is of course always in the cards) a crash that looked comparatively benign could lead to an fs that's not only unmountable but unfixable; how metadata that's effectively a single point of failure could not have backup copies designed in that are neither stale nor left to the elements, seems awfully fragile -- but I can accept it. Repair is out. Recovery it is, then. I'd like to try and build this rescue branch of yours. Does it have to be the whole thing, or can btrfs alone be built against the headers of the distro kernel somehow, or can the distro kernel source be patched with the rescue stuff? Git wasn't a thing the last time I played with kernels, a shove in the right direction would be appreciated. Relapse prevention. "Update everything and pray it's either been fixed or at least isn't triggered any more" isn't all to confidence-inspiring. Desktop computers running remotely current software will crash from time to time, after all, if not amdgpu then something else. At which point we're back at "a crash shouldn't have caused this". If excerpts from the damaged image are any help in finding the actual issue, I can keep it around for a while. Disaster recovery. What do people use to quickly get back up and running from bare metal that integrates well with btrfs (and is suitable just for a handful of machines)? Cheers, C. P.S.: MemTest86 hasn't found anything in (as yet) 6 passes, nothing glaringly wrong with the RAM.
