> Your premise is entirely wrong. How else would I determine what CPUs are fast or reliable? Buy dozens of them and stress-test them all? No, I use online sites like cpu-monkey.com that compare different CPUs' features and performance according to various benchmarks, for the performance part at least. For reliability, what way can you possibly think of other than simply aggregating user ratings (i.e. anecdotes)? If you aren't running a datacenter or something, you have no practical alternative.

My point is just that anecdotes alone don't tell you much. I'm not suggesting that everyone needs to conduct studies on how reliable something is, but if nobody has done the groundwork then the best thing we can really say is we're not sure how stable it is because the best evidence is not very good and it conflicts.

> Companies using something doesn't always mean it's any good, especially for individual/consumer use. Companies can afford teams of professionals to manage stuff, and they can also make their own custom versions of things (esp. true with OSS code). They're also using things in ways that aren't comparable to individuals. These companies may be using btrfs in a highly feature-restricted way that they've found, through testing, is safe and reliable for their use case.

For Synology you can take a look at what they're shipping since they're shipping it to consumers. It does seem like they're not using many of the volume management features, instead using some proprietary volume management scheme on the block layer. However otherwise there's nothing particularly special that I can see, it's just btrfs. Other advanced features like transparent compression are available and exposed in the UI.

(edit: Small correction. While I'm still pretty sure Synology has custom volume management for RAID which works on the block level, as it turns out, they are actually using btrfs subvolumes as well.)

I think the Synology case is an especially interesting bit of evidence because it's gotta be one of the worst cases of shipping a filesystem, since you're shipping it to customer machines you don't control and can't easily inspect later. It's not the only case of shipping btrfs to the customer either, I believe ChromeOS does this and even uses subvolumes, though I didn't actually look for myself when I was using it so I'm not actually 100% sure on that one.

> This is all true, but ZFS has generally all the same features, yet I don't see remotely as many testimonials from people saying "ZFS ate my data!" as I have with btrfs over the years. Maybe btrfs has gotten better over time, but as the American car manufacturers found out, it takes very little time to ruin your reputation for reliability, and a very long time to repair that reputation.

In my opinion, ZFS and other Solaris technologies that came out around that time period set a very high bar for reliable, genuinely innovative system features. I think we're going to have to live with the fact that just having a production-ready filesystem dropped onto the world is not going to be the common case, especially in the open source world: the filesystem will need to go through its growing pains in the open.

Btrfs has earned a reputation as the perpetually-unfinished filesystem. Maybe it's tainted and it will simply never approach the degree of stability that ZFS has. Or, maybe it already has, and it will just take a while for people to acknowledge it. It's hard to be sure.

My favorite option would be if I just simply don't have to find out, because an option arrives that quickly proves itself to be much better. bcachefs is a prime contender since it not only seems to have better bones but it's also faster than btrfs in benchmarks anyways (which is not saying much because btrfs is actually quite slow.) But for me, I'm still waiting. And until then, ZFS is not in mainline Linux, and it never will be. So for now, I'm using btrfs and generally OK recommending it for users that want more advanced features than ext4 can offer, with the simple caveat that you should always keep sufficient backups of your important data at all times.

I only joined in on this discussion because I think that the btrfs hysteria train has gone off the rails. Btrfs is a flawed filesystem, but it continues to be vastly overstated every time it comes up. It's just, simply put, not that bad. It does generally work as expected.