Linux

Been using BTRFS on a couple NAS servers for 4+ years. Also did raid1 BTRFS over two USB hard drives connected to a Pi4 (yes this should be absolutely illegal).

The USB raid1 had a couple checksum errors that were easily fixed via scrub last year and the other two servers have been running without any issues. I assume it's been fine since they're all connected to a UPS and since I run weekly scrubs.

I enjoyed CoW and snapshots so much that I've been using it on my main Arch install's (I use Arch btw) root drive and storage drives (in BTRFS raid1) for the last 4 months without issue.

I've been running ZFS in the form of FreeNAS/TrueNAS in production environments for the past 12 years or so. Started with around 5TB and currently have nearly 300TB across several servers. Mostly NFS nowadays, but have shared out SMB and iSCSI.

No data loss. Drives have been easy to replace and re-silver. We have had a couple instances where a failing ZIL or L2ARC has crashed a storage server and taken storage offline, but removing/replacing the log device got us up and running without data loss.

Btrfs I only have experience on home systems. It has reliably stored my data for several years now, but I'm about to put it to the test this weekend. I plan on adding 4x8TB disks to a 4TB mirror to turn it into a 20TB RAID10. Wish me luck!

I think zfs is a pretty cool guy. Eh copy on write and doesn't afraid of anything

I have had great luck with my users' home directories on ZFS. No issues in years. Used to have issues, and on those days I was glad root was on ext3.

I had issues with btrfs about 10 years ago. It is much better now.

Both experiences with Linux.

A different ZFS partition per user is really helpful for quota and migration.

Been using Btrfs for a year, I once had an issue that my filesystem was read only, I went to the Btrfs reddit and after some troubleshooting it turned out that my ssd was dying, I couldn't believe it at first because my SMART report was perfectly clean and the SSD was only 2 years old, then a few hours later SMART began reporting thousands of dead sectors.

The bloody thing was better than smart at detecting a dying ssd lol.

At some, long ago, the Ubuntu installer was offering to use zfs for the boot and root partitions. That sounded like a good idea and worked great for a long time, automatic snapshots, options to restore state at boot etc.

Until my generous boot partition started to run out if space with all the snapshots (which were setup automatically and no obvious way to configure) OK no big deal, write a bash script that finds the old snapshots and delete them manually whenever boot is full again.

Then one day recently my laptop wouldn't boot anymore, Grub could no longer read the zfs on boot. Managed to boot with USB installation image, read zsf and chroot. Tried alot of things but in the end killed zfs and replace with ext4. Then made it boot again.

Apparently I'm not the only one with this issue.

There's no reason you couldn't; btrfs is pretty stable.

Edit: Going on five years of using btrfs on production servers (storing and processing data on a 24x7 basis).

I did my first BTRFS setup over the weekend. I followed the Arch wiki to set up what I thought was RAID 1 only to find out nearly a TB of copying later that it was splitting the data between the drives, not mirroring them (only the metadata was in R1.) One command later and I'd converted the filesystem to true RAID 1. I feel like any other system would require a total redo of the entire FS, but BTRFS did it flawlessly.

I'm still confused, however, as it seems RAID 1 only works with two drives from what I've read. Is that true? Why?

Btrfs is good for small systems with 1-2 disks. ZFS is good for many disks and benefits heavily from ram. ZFS also has specially disks.

Linux does not support ZFS as well as operating systems like OpenBSD or OpenIndiana, but I do use it on my Ubuntu box for my backup array. It is not the best setup: RAID-Z over USB is not at all guaranteed to keep your data safe, but it was the most economical thing I was able to build myself, and it gets the job done well enough with regular scrubbing to give me piece of mind about at least having one other reliable copy of my data. And I can write files to it quickly, and take snapshots of the state of the filesystem if need be.

I used to use Btrfs on my laptop and it worked just fine, but I did have trouble once when I ran out of disk space. A Btrfs filesystem puts itself into read-only mode when that happens, and that makes it tough to delete files to free-up space. There is a magic incantation that can restore read-write functionality, but I never learned what it was, I just decided to stop using it because Btrfs is pretty clearly not for home PC use. Freezing the filesystem in read-only mode makes sense in a data-center scenario, but not for a home user who might want to try to erase data so one can keep using it normally. I might consider using Btrfs in place of ZFS on a file server, though ZFS does seem to provide more features and seems to be somewhat better tested and hardened.

There is also BCacheFS now as an alternative to Btrfs, but it is still fairly new, and not widely supported by default installations. I don't know how stable it is or how well it compares to Btrfs, but I thought I would mention it.

Stick with ext3/ext4

After 4 years on btrfs I haven't had a single issue, I never think about it really. Granted, I have a very basic setup. Snapper snapshots have saved me a couple of times, that aspect of it is really useful.

I haven't used them professionally but I've been using ZFS on my home router (OPNsense) and NAS (TrueNAS with RAID-Z2) for many years without problem. I've used Btrfs on laptops and desktops with OpenSUSE Tumbleweed for the past year and a bit, also without problem. Btrfs snapshots have saved me a couple of times when I messed something up. Both seem like solid filesystems for everyday use.