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Comment by shrubble | Hacker News Reader

The btrfs code quality seems less than ZFS, based on the reports I have read.

Last I heard (~8 years ago), the RAID-like functionality in btrfs was very unstable and crash-prone. The impression I got was that there was not a lot of interest in fixing this. Then bcachefs came and ... appears to have gone nowhere AFAICT.

The non-RAID part of btrfs appears to be stable. It's the default filesystem on openSUSE and SLES. But I don't think it's ever going to reach feature parity with ZFS.

> Then bcachefs came and ... appears to have gone nowhere AFAICT.

I heard the developer got sidetracked into writing himself an AI girlfriend. (Not sarcasm)

hah, you weren't joking... https://poc.bcachefs.org/ https://www.theregister.com/2026/02/25/bcachefs_creator_ai/

People love to imagine all sorts of salacious things.

Thank you for Bcachefs. Truly an amazing project.

And to the grandparent post's point, since the split with the kernel there've been two big new feature releases: reconcile, which puts our data and drive management head and shoulders above other filesystems - and erasure coding was just released, 1.37 came out a few days ago.

btrfs is suffering from a lot of old bad publicity and some poor design decisions around RAID.

But by now it is a great file system if you don't go near RAID5/6. btrfs has its flaws (ZFS has its own flaws!). However:

- It's used a lot, especially by facebook and Redhat (on fedora)

- Gets a lot of testing

- Sees a lot of bug fixes

- Has a lot of features

I haven't read btrfs code but given that it is a popular file system and Linux code quality tends to be good in popular subsystems I would hesitate to say its code quality is worse than ZFS in any way.

btrfs is pathetic when it comes to performance. So no, thanks.

https://www.phoronix.com/review/linux-70-filesystems

ZFS is worse than btrfs in performance.

Check out https://www.phoronix.com/review/linux-617-filesystems/5 "Geometric Mean of all test results". You will find that OpenZFS is ~35% slower than btrfs.

I love ZFS but I am aware about the performance it delivers.

but real life workload are not "Geometric Mean".

When I use firefox, sqlite performance matter more than any random benchmark. The same benchmark shows sqlite is 3x faster on zfs.

> but real life workload are not "Geometric Mean".

A good benchmark suite consists of good benchmarks chosen carefully. These benchmarks are not chosen randomly. They represent diverse ways to "stress" or exercise the system. Real life workloads are indeed closer to "Geometric Mean" of various benchmarks by definition because real life workloads are diverse. Not everything would be like sqlite3 which is single pattern of file system usage.

Geekbench, Cinebench, 3DMark etc. are all averages or geometric means of various benchmarks also.

> When I use firefox, sqlite performance matter more than any random benchmark.

You've selected a single benchmark (sqlite) and said it's so important to you that it overrides everything else when you are comparing ZFS vs btrfs.

If you feel that a single benchmark like sqlite is good enough then that is fine -- your decision. I am hesitant to do the same and prefer geometric mean.

Last I tried zfs was far far worse on reads arc couldn't satisfy, and all writes

In real world scenarios, where file based backups fail, one needs to add at least lvm.

And only than those benchmarks would be more interesting to me.

Be specific. Why do you need LVM? What for, what do you do with it?

Secondly: are you aware that ZFS includes what LVM does on Linux, and so you don't need a separate tool for it? This makes the comparison tricky but it's important to consider.

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