All problems are edge cases, to some degree or another. The only real question is how far out those edges are, and whether users are likely to bump into them.
Edge cases like Raid5/6 which had the write hole issue approximately a decade after btrfs was released. At some point you say "This filesystem has lost so much of my data that I will never return to it."
Burn me once, shame on you, burn me twice, shame on me. If you purchased a new ford and that car fell apart a week later, would you ever buy a ford again? Some will, most wont.
A better analogy would be if the car got you in an accident. I don’t care if something breaks quickly as long as that means it can be returned or replaced.
I agree, I love BTRFS and have used it for ages, including some small scale production systems. But I know it still has some edge cases as you mention, which made me wonder: what is the impediment to having those cases fixed? BTRFS has been around long enough and even has some decent commercial support from a few vendors, so it seems like we can't just discount it as "it's open source and nobody is motivated to fix those long tail problems." Is there some kind of design issue that makes them hard?
edit: sorry, cheap shot at Facebook. I have no idea why BTRFS edge cases are not being fixed.
What I do know is that ZFS recently released a feature specifically for the hobbyist/frugal community. The feature allows you to grow an existing RAID array, something a financially sound business would never do. So no customer of anyone supporting ZFS would ever use this, and it took significant effort of ZFS developers to implement this. Not to mention that introducing feature potentially introduces weird behaviour in ZFS that might endanger its (reputation of) stability.
I'm super happy with it, (as my company was not in fact financially sound when we invested in our on-premise storage hardware), but if I was CEO of ZFS I'm not sure I'd sign off on it.
Point was the post is about losing reiserfs, and people are presenting virtues of zfs and btrfs as reasons why we don't need reiserfs any more, and this virtue of zfs is unremarkable.
That is very informative about the edge cases for btrfs. My question was what are the edge cases in the other filesystems which put them on a level playing field with btrfs considersing it still has so many.