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by thomaszander 2000 days ago
> Why does btrfs have those issues compared to other filesystems?

As someone that has built infrastructure on BtrFS for years, the scary stories are mostly just hot air and the stability of other filesystems is really not significantly better.

Bugs like this happen, this is why Linus releases many release-candiates every kernel, this one got through as 10 was a rather massive kernel and there were several regressions. Including one that caused a new release just hours after the supposedly final one. Distros wait a bit longer before shipping an updated kernel and none of these hit actual users.

As far as I know there is no reason to abstain from using Btrfs. When Fedora talked about not using it, they had as reason that they had no in-house expertise.

4 comments

> As someone that has built infrastructure on BtrFS for years, the scary stories are mostly just hot air and the stability of other filesystems is really not significantly better.

I've lost 2 root filesystems to btrfs, on a laptop with only 1 drive (read: not even using RAID). Have you considered that you're just lucky?

In my experience, the stories are real. Our entire company was offline for a day when our central storage server quit accepting writes despite having over 50% free space. That's when I learned the hard way about the data/metadata split (something I was aware of but wasn't exactly top of mind) and BTRFS balance. You can certainly say it was my fault for not reading ALL the documentation before using BTRFS, and I'd find it hard to disagree, but any other filesystem wouldn't have had this problem.

I can't speak to if there are other foot-guns waiting around or how common problems like this are because we migrated back to FreeBSD and ZFS shortly after that experience. I do know they have since updated BTRFS to make that scenario less likely (but still not impossible).

This is exactly my experience as well.

Btrfs is the C++ of file systems: it’s powerful and works for a great many people. But the tooling is intimidating to new comers and unless you know exactly what you’re doing, it’s a ticking time bomb due to the plethora of foot guns and hidden traps.

This is why some people claim to have success with it while a great many other people, rightfully, claim it’s not yet ready for prime time.

ZFS, on the other hand, has not only protected me against failing hardware but it also has sane defaults and easy to use tooling thus protecting me against my own stupidity.

I don't think it's your fault in any way.

We expect filesystems to work robustly. We do not expect them to fail after an arbitrary time interval merely by being used. Even terrible filesystems like FAT don't do that. They might get fragmented and slow, but they don't just stop. I find it incredible that this is often minimised by people; it's a complete show-stopper irrespective of the other problems Btrfs has.

I made exactly the same migration you did. ZFS has been solid, and it does exactly what it says on the tin.

Does Fedora now have in-house expertise now that they've decided to make Btrfs default?
Some Facebook btrfs devs agreed to help out. FB runs Fedora/CentOS + btrfs root on most of its systems.
Thank you for posting your experience!