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Brtfs only exists as Oracle's "replacement" for ZFS, to hedge their bets in case they couldn't buy Sun. Oracle bought sun in 2010, that has been 12 years. They

Brtfs only exists as Oracle's "replacement" for ZFS, to hedge their bets in case they couldn't buy Sun. Oracle bought sun in 2010, that has been 12 years. They merged the Btrfs and ZFS teams, they then worked on ZFS entirely with no Btrfs work, and then basically reassigned, fired, or otherwise dissolved the ZFS team when it became clear that OpenZFS (Sun's chosen steward for ZFS) could not be swayed. Btrfs has had no real work done on it since then, and anyone that is actually serious about data storage has moved to ZFS, or has left POSIX filesystems entirely.

EastToWest 5y ago
> Btrfs has had no real work done on it since then, and anyone that is actually serious about data storage has moved to ZFS, or has left POSIX filesystems entirely. I'm not very familiar with this space, but if this were true why would Fedora use Btrfs by default? Also on Fedora wiki [0] -- Btrfs is a mature, well-understood, and battle-tested file system, used on both desktop/container and server/cloud use-cases -- which seems to contradict what you said. [0] https://fedoraproject.org/wiki/Changes/BtrfsByDefault https://fedoraproject.org/wiki/Changes/BtrfsByDefault
- naranha 5y ago
  Apparently it used at facebook a lot too. https://lwn.net/Articles/824855/ https://lwn.net/Articles/824855/
jcalvinowens 5y ago
This is one of the most laughably ignorant posts I've ever seen on the internet. > Btrfs has had no real work done on it since then, and anyone that is actually serious about data storage has moved to ZFS, or has left POSIX filesystems entirely Btrfs is the most actively developed filesystem in the kernel, both by LOC changed and the number of contributors. Facebook publicly stated that they run BTRFS on every webserver years ago. ZFS is an antiquated joke. It is wed to the memory allocator in Solaris, and requires that you permanently reserve 1GB of RAM per 1TB of disk space, which is an impractical constraint in the modern world. ZFS is also full of cute little wasteful "innovations" like 128-bit file size support. I don't know what planet you're from, but it's not mine :)
- uniqueuid 5y ago
  Please correct me if I'm wrong, but the "1GB ram per TB" is for the de-duplication table. ZFS' memory cache (ARC) by default uses up to 50% of system ram and frees this under pressure. You can also set it lower.
  - jcalvinowens 5y ago
    Yes, this is what I'm talking about. With respect to ARC, it gets along very poorly with the native page cache and memory allocator. I would add that BTRFS has no such requirements for deduplication.
    - db48x 5y ago
      That’s because the btrfs deduplicator is quite a different animal. You could just as easily run fdupes or something similar. Meanwhile ZFS is doing something much more ambitious. In any case, I don’t think that either of them are worth using in most cases. Deduplication is just too expensive to be worth it.
      - Dylan16807 5y ago
        > You could just as easily run fdupes or something similar. If you only deduplicate whole files and soft links or hard links are suitable for your situation.
        db48x 5y ago
        That’s not the aspect of the deduplication process that I was referring to. Btrfs only supports offline deduplication, where you periodically run a process that searches for duplicate blocks and combines them. Meanwhile ZFS supports online deduplication, where every block written is checked against an index to see if it is a duplicate of some existing block. That index is what takes up the memory that jcalvinowens complained about. When deduplication is turned on, ZFS keeps that whole index in memory all of the time. Meanwhile btrfs only needs that index to be loaded while the deduplicator is running, so it doesn’t show up most of the time. Personally I don’t think that either is really worth the cost; the benefit is so small that the cost isn’t worth paying.
nimbius 5y ago
>Btrfs has had no real work done on it since then changelog seems to refute this point entirely. https://btrfs.wiki.kernel.org/index.php/Changelog https://btrfs.wiki.kernel.org/index.php/Changelog >anyone that is actually serious about data storage has moved to ZFS sometimes data storage doesnt have to scale, and thats okay. there are still plenty of use cases for lvm/xfs/mdadm in environments that dont need Google levels of service. im "serious" about data storage and run raid10 btrfs. >or has left POSIX filesystems entirely. oh get off the cross. redhat intentionally threw backing into XFS to make it functional with Ceph. just because BTRFS has issues with RAID5 (arguably the worst RAID) doesnt mean the whole of POSIX storage has been relegated to the ash heap.
- topspin 5y ago
  > redhat intentionally threw backing into XFS to make it functional with Ceph. Can you elaborate on that? Is the about pre-bluestore backing of Ceph or... something else?

EastToWest 5y ago

> Btrfs has had no real work done on it since then, and anyone that is actually serious about data storage has moved to ZFS, or has left POSIX filesystems entirely. I'm not very familiar with this space, but if this were true why would Fedora use Btrfs by default? Also on Fedora wiki [0] -- Btrfs is a mature, well-understood, and battle-tested file system, used on both desktop/container and server/cloud use-cases -- which seems to contradict what you said. [0] https://fedoraproject.org/wiki/Changes/BtrfsByDefault https://fedoraproject.org/wiki/Changes/BtrfsByDefault

naranha 5y ago
Apparently it used at facebook a lot too. https://lwn.net/Articles/824855/ https://lwn.net/Articles/824855/

jcalvinowens 5y ago

This is one of the most laughably ignorant posts I've ever seen on the internet. > Btrfs has had no real work done on it since then, and anyone that is actually serious about data storage has moved to ZFS, or has left POSIX filesystems entirely Btrfs is the most actively developed filesystem in the kernel, both by LOC changed and the number of contributors. Facebook publicly stated that they run BTRFS on every webserver years ago. ZFS is an antiquated joke. It is wed to the memory allocator in Solaris, and requires that you permanently reserve 1GB of RAM per 1TB of disk space, which is an impractical constraint in the modern world. ZFS is also full of cute little wasteful "innovations" like 128-bit file size support. I don't know what planet you're from, but it's not mine :)

uniqueuid 5y ago
Please correct me if I'm wrong, but the "1GB ram per TB" is for the de-duplication table. ZFS' memory cache (ARC) by default uses up to 50% of system ram and frees this under pressure. You can also set it lower.
- jcalvinowens 5y ago
  Yes, this is what I'm talking about. With respect to ARC, it gets along very poorly with the native page cache and memory allocator. I would add that BTRFS has no such requirements for deduplication.
  - db48x 5y ago
    That’s because the btrfs deduplicator is quite a different animal. You could just as easily run fdupes or something similar. Meanwhile ZFS is doing something much more ambitious. In any case, I don’t think that either of them are worth using in most cases. Deduplication is just too expensive to be worth it.
    - Dylan16807 5y ago
      > You could just as easily run fdupes or something similar. If you only deduplicate whole files and soft links or hard links are suitable for your situation.
      - db48x 5y ago
        That’s not the aspect of the deduplication process that I was referring to. Btrfs only supports offline deduplication, where you periodically run a process that searches for duplicate blocks and combines them. Meanwhile ZFS supports online deduplication, where every block written is checked against an index to see if it is a duplicate of some existing block. That index is what takes up the memory that jcalvinowens complained about. When deduplication is turned on, ZFS keeps that whole index in memory all of the time. Meanwhile btrfs only needs that index to be loaded while the deduplicator is running, so it doesn’t show up most of the time. Personally I don’t think that either is really worth the cost; the benefit is so small that the cost isn’t worth paying.

nimbius 5y ago

>Btrfs has had no real work done on it since then changelog seems to refute this point entirely. https://btrfs.wiki.kernel.org/index.php/Changelog https://btrfs.wiki.kernel.org/index.php/Changelog >anyone that is actually serious about data storage has moved to ZFS sometimes data storage doesnt have to scale, and thats okay. there are still plenty of use cases for lvm/xfs/mdadm in environments that dont need Google levels of service. im "serious" about data storage and run raid10 btrfs. >or has left POSIX filesystems entirely. oh get off the cross. redhat intentionally threw backing into XFS to make it functional with Ceph. just because BTRFS has issues with RAID5 (arguably the worst RAID) doesnt mean the whole of POSIX storage has been relegated to the ash heap.

topspin 5y ago
> redhat intentionally threw backing into XFS to make it functional with Ceph. Can you elaborate on that? Is the about pre-bluestore backing of Ceph or... something else?