About a year ago I switched to ZFS for Proxmox so that I wouldn’t be running technology preview.

Btrfs gave me no issues for years and I even replaced a dying disk with no issues. I use raid 1 for my Proxmox machines. Anyway I moved to ZFS and it has been a less that ideal experience. The separate kernel modules mean that I can’t downgrade the kernel plus the performance on my hardware is abysmal. I get only like 50-100mb/s vs the several hundred I would get with btrfs.

Any reason I shouldn’t go back to btrfs? There seems to be a community fear of btrfs eating data or having unexplainable errors. That is sad to hear as btrfs has had lots of time to mature in the last 8 years. I would never have considered it 5-6 years ago but now it seems like a solid choice.

Anyone else pondering or using btrfs? It seems like a solid choice.

  • cmnybo@discuss.tchncs.deEnglish
    47·
    2 days ago

    Don’t use btrfs if you need RAID 5 or 6.

    The RAID56 feature provides striping and parity over several devices, same as the traditional RAID5/6. There are some implementation and design deficiencies that make it unreliable for some corner cases and the feature should not be used in production, only for evaluation or testing. The power failure safety for metadata with RAID56 is not 100%.

    https://btrfs.readthedocs.io/en/latest/btrfs-man5.html#raid56-status-and-recommended-practices

    • lurklurk@lemmy.worldEnglish
      9·
      1 day ago

      Or run the raid 5 or 6 separately, with hardware raid or mdadm

      Even for simple mirroring there’s an argument to be made for running it separately from btrfs using mdadm. You do lose the benefit of btrfs being able to automatically pick the valid copy on localised corruption, but the admin tools are easier to use and more proven in a case of full disk failure, and if you run an encrypted block device you need to encrypt half as much stuff.

    • Eideen@lemmy.worldEnglish
      3·
      1 day ago

      I have no problem running it with raid 5/6. The important thing is to have a UPS.

      • dogma11@lemmy.worldEnglish
        1·
        1 day ago

        I’ve been running a btrfs storage array with data on raid5 and metadata I believe raid1 for the last 5 or so years and have yet to have a problem because of it. I did unfortunately learn not to fully trust the windows btrfs driver but was fortunately able to restore from backups and redownloading.

        I wouldn’t hesitate to set it up again for myself or anybody else, and adding a UPS would be icing on the cake. (I added UPS to my setup this last summer)

    • Anonymouse@lemmy.worldEnglish
      2·
      1 day ago

      I’ve got raid 6 at the base level and LVM for partitioning and ext4 filesystem for a k8s setup. Based on this, btrfs doesn’t provide me with any advantages that I don’t already have at a lower level.

      Additionaly, for my system, btrfs uses more bits per file or something such that I was running out of disk space vs ext4. Yeah, I can go buy more disks, but I like to think that I’m running at peak efficiency, using all the bits, with no waste.

      • sugar_in_your_tea@sh.itjust.worksEnglish
        2·
        23 hours ago

        btrfs doesn’t provide me with any advantages that I don’t already have at a lower level.

        Well yeah, because it’s supposed to replace those lower levels.

        Also, BTRFS does provide advantages over ext4, such as snapshots, which I think are fantastic since I can recover if things go sideways. I don’t know what your use-case is, so I don’t know if the features BTRFS provides would be valuable to you.

        • Anonymouse@lemmy.worldEnglish
          1·
          6 hours ago

          Generally, if a lower level can do a thing, I prefer to have the lower level do it. It’s not really a reason, just a rule of thumb. I like to think that the lower level is more efficient to do the thing.

          I use LVM snapshots to do my backups. I don’t have any other reason for it.

          That all being said, I’m using btrfs on one system and if I really like it, I may migrate to it. It does seem a whole lot simpler to have one thing to learn than all the layers.

          • sugar_in_your_tea@sh.itjust.worksEnglish
            1·
            5 hours ago

            Yup, I used to use LVM, but the two big NAS filesystems have a ton of nice features and they expect to control the disk management. I looked into BTRFS and ZFS, and since BTRFS is native to Linux (some of my SW doesn’t support BSD) and I don’t need anything other than RAID mirror, that’s what I picked.

            I used LVM at work for simple RAID 0 systems where long term uptime was crucial and hardware swaps wouldn’t likely happen (these were treated like IOT devices), and snapshots weren’t important. It works well. But if you want extra features (file-level snapshots, compression, volume quotas, etc), BTRFS and ZFS make that way easier.