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It is (soon) officially in kernel, as opposed to zfs. It has a more limited feature set and said to have simpler codebase than zfs/btrfs. It has a single outst

It is (soon) officially in kernel, as opposed to zfs. It has a more limited feature set and said to have simpler codebase than zfs/btrfs. It has a single outstanding non-stable feature. It seems to be in active development, while btrfs seems to have become stagnant/abandonware before it was finished/stabilised completely. I have read several horror stories about data loss, so I have avoided it so far. On the other hand it is not widely deployed yet, there is less accumulated knowledge than in case of zfs. I'm looking forward to trying it in my NAS when buying new disks next year. The COW snapshots would fit my needs (automatic daily snapshots, weekly backups). (Now using LUKS+LVM+ext4, this would give a better, more integrated, deduplicated solution, I have lots of duplicated data right now)

viraptor 3y ago
> while btrfs seems to have become stagnant/abandonware before it was finished/stabilised completely Why would you think so? I can't remember the last time a kernel was released without something at least a bit exciting about btrfs https://kernelnewbies.org/LinuxChanges#Linux_6.5.File_systems https://kernelnewbies.org/LinuxChanges#Linux_6.5.File_system...
- Geezus_42 3y ago
  Because they still haven't fixed the write hole issues in certain RAID configurations,which have been known for a decade or more.
  - viraptor 3y ago
    A project not finishing some feature is not the same as being abandoned. It seems lots of people are happy to use btrfs in production without that raid mode. In other words, for all the complaining about raid5 that happens every time btrfs is mentioned, you'd think there would be at least one person who cares enough to implement it. Yet people use it in production and keep improving the other parts of that project instead.
    - Geezus_42 3y ago
      It's fine for single a single disk or something that presents as a single disk, like a SAN. RAID1 seems fine also. I really wanted to love it, but after it ate my data a couple of times, I gave up trying to use it for mass storage. At that time they didn't have warnings in the documentation and had stated that RAID5/6 were basically complete. I found using mirrored vdevs in ZFS much easier to manage and much more stable.
      - wtallis 3y ago
        > I found using mirrored vdevs in ZFS much easier to manage and much more stable. That's not exactly a fair comparison. If you restricted your usage of btrfs to a similarly narrow range of features, you would probably have had a much better experience.
      - creatonez 3y ago
        RAID1 in Btrfs is not entirely fine. It won't nuke your data and there is no write-hole issue, but if a disk fails you'll have to go into a read-only mode during the rebuild and deal with various hurdles in getting it rebuilt.
        wtallis 3y ago
        > but if a disk fails you'll have to go into a read-only mode during the rebuild and deal with various hurdles in getting it rebuilt. I can't say for sure that this never happens, but that's certainly not been the failure mode for any of the drive failures my btrfs RAID1 has experienced. I don't think I've ever needed to reboot or even remount my filesystem, just replace the failed drive (physically, then in software). But I always have more than two drives in the filesystem, so a single drive failure only puts a fraction of my data at risk, not everything.
        viraptor 3y ago
        > if a disk fails you'll have to go into a read-only mode during the rebuild That's not correct, you can rebuild online. The readonly mode is only relevant when you reboot during the failure and don't have the right options set on the volume. But you totally can replace a live drive without affecting the availability.
- creatonez 3y ago
  > I can't remember the last time a kernel was released without something at least a bit exciting about btrfs They are fixing the fixable issues, but the on-disk format still makes some gotchas inevitable. It sounds like there's never going to be a great solution to live rebuilding of redundancy.

viraptor 3y ago

> while btrfs seems to have become stagnant/abandonware before it was finished/stabilised completely Why would you think so? I can't remember the last time a kernel was released without something at least a bit exciting about btrfs https://kernelnewbies.org/LinuxChanges#Linux_6.5.File_systems https://kernelnewbies.org/LinuxChanges#Linux_6.5.File_system...

Geezus_42 3y ago
Because they still haven't fixed the write hole issues in certain RAID configurations,which have been known for a decade or more.
- viraptor 3y ago
  A project not finishing some feature is not the same as being abandoned. It seems lots of people are happy to use btrfs in production without that raid mode. In other words, for all the complaining about raid5 that happens every time btrfs is mentioned, you'd think there would be at least one person who cares enough to implement it. Yet people use it in production and keep improving the other parts of that project instead.
  - Geezus_42 3y ago
    It's fine for single a single disk or something that presents as a single disk, like a SAN. RAID1 seems fine also. I really wanted to love it, but after it ate my data a couple of times, I gave up trying to use it for mass storage. At that time they didn't have warnings in the documentation and had stated that RAID5/6 were basically complete. I found using mirrored vdevs in ZFS much easier to manage and much more stable.
    - wtallis 3y ago
      > I found using mirrored vdevs in ZFS much easier to manage and much more stable. That's not exactly a fair comparison. If you restricted your usage of btrfs to a similarly narrow range of features, you would probably have had a much better experience.
    - creatonez 3y ago
      RAID1 in Btrfs is not entirely fine. It won't nuke your data and there is no write-hole issue, but if a disk fails you'll have to go into a read-only mode during the rebuild and deal with various hurdles in getting it rebuilt.
      - wtallis 3y ago
        > but if a disk fails you'll have to go into a read-only mode during the rebuild and deal with various hurdles in getting it rebuilt. I can't say for sure that this never happens, but that's certainly not been the failure mode for any of the drive failures my btrfs RAID1 has experienced. I don't think I've ever needed to reboot or even remount my filesystem, just replace the failed drive (physically, then in software). But I always have more than two drives in the filesystem, so a single drive failure only puts a fraction of my data at risk, not everything.
      - viraptor 3y ago
        > if a disk fails you'll have to go into a read-only mode during the rebuild That's not correct, you can rebuild online. The readonly mode is only relevant when you reboot during the failure and don't have the right options set on the volume. But you totally can replace a live drive without affecting the availability.
creatonez 3y ago
> I can't remember the last time a kernel was released without something at least a bit exciting about btrfs They are fixing the fixable issues, but the on-disk format still makes some gotchas inevitable. It sounds like there's never going to be a great solution to live rebuilding of redundancy.