Selfhosted

I've been using single-disk btrfs for my rootfs on every system for almost a decade. Great for snapshots while still being an in-tree driver. I also like being able to use subvolumes to treat / and /home (maybe others) similar to separate filesystems without actually being different partitions.

I had used it for my NAS array too, with btrfs raid1 (on top of luks), but migrated that over to ZFS a couple years ago because I wanted to get more usable storage space for the same money. btrfs raid5 is widely reported to be flawed and seemed to be in purgatory of never being fixed, so I moved to raidz1 instead.

One thing I miss is heterogenous arrays: with btrfs I can gradually upgrade my storage one disk at a time (without rewriting the filesystem) and it uses all of my space. For example, two 12TB drives, two 8TB drives, and one 4TB drive adds up to 44TB and raid1 cuts that in half to 22TB effective space. ZFS doesn't do that. Before I could migrate to ZFS I had to commit to buying a bunch of new drives (5x12TB not counting the backup array) so that every drive is the same size and I felt confident it would be enough space to last me a long time since growing it after the fact is a burden.

One day I had a power outage and I wasn't able to mount the btrfs system disk anymore. I could mount it in another Linux but I wasn't able to boot from it anymore. I was very pissed, lost a whole day of work

The question is how do you get a bad performance with ZFS?

I just tried to read a large file and it gave me uncached 280 MB/s from two mirrored HDDs.

The fourth run (obviously cached) gave me over 3.8 GB/s.

I am using btrfs on raid1 for a few years now and no major issue.

It's a bit annoying that a system with a degraded raid doesn't boot up without manual intervention though.

Also, not sure why but I recently broke a system installation on btrfs by taking out the drive and accessing it (and writing to it) from another PC via an USB adapter. But I guess that is not a common scenario.

One time I had a power outage and one of the btrfs hds (not in a raid) couldn't be read anymore after reboot. Even with help from the (official) btrfs mailinglist It was impossible to repair the file system. After a lot of low level tinkering I was able to retrieve the files, but the file system itself was absolutely broken, no repair process was possible. I since switched to zfs, the emergency options are much more capable.

If it didn't give you problems, go for it. I've run it for years and never had issues either.

Not proxmox-specific, but I've been using btrfs on my servers and laptops for the past 6 years with zero issues. The only times it's bugged out is due to bad hardware, and having the filesystem shouting at me to make me aware of that was fantastic.

The only place I don't use zfs is for my nas data drives (since I want raidz2, and btrfs raid5 is hella shady) but the nas rootfs is btrfs.

Raid 5/6, only bcachefs will solve it

Btrfs only has issues with raid 5. Works well for raid 1 and 0. No reason to change if it works for you

Using it here. Love the flexibility and features.

I run it now because I wanted to try it. I haven't had any issues. A friend recommended it as a stable option.

Do you rely on snapshotting and journaling? If so backup your snapshots.