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Comment by jaytaylor | Hacker News Reader

Do any of you know why btrfs is being pushed rather than [the more mature and super flexible] zfs?

There is lots of debate if you search google for comparisons, though they usually seem to end up favoring zfs, which is why I'm a little perplexed here.

e.g. http://rudd-o.com/linux-and-free-software/ways-in-which-zfs-...

Notably, I also ran into a show-stopping kernel bug [0] with btrfs within a day or two of the first production rollout of ShipBuilder [1] (it's an open-source self-hosted PaaS Heroku clone). Since switching to zfs there have been zero file-system related issues with any ShipBuilder production or staging environment so far as I am aware.

[0] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1214085

[1] http://shipbuilder.io

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Because it's illegal for anyone except Oracle to include ZFS with a Linux distribution, amongst other things.

Take it up with Sunacle.

That's a pity, like Ksplice

Are you sure? I thought that ZFS for Linux can be distributed, but, only in source code form. So you would have to distributed the source code, then, build the ZFS module for it after / during installation.

That's pretty much it, except that nobody big has actually tried doing that (distributing an install CD which specifically builds ZFS as part of the standard install process), therefore it's not been in courts, therefore it's not proven that it's legally safe to do so, therefore anyone larger than a small business is unlikely to build on top of it.

As I get it, ZFS core (as necessary for GRUB to read the filesystem) is available under GPL. While not enough, this could've been a starting point.

However, the main issue is ZFS is also patent encumbered, so re-implementing (even with clean-room approach) it may mean meeting with Oracle's lawyers.

That's sad, considering btrfs still suffers from internal fragmentation issue, as Edward Shishkin had shown in 2010.

> That's sad, considering btrfs still suffers from internal fragmentation issue, as Edward Shishkin had shown in 2010.

True, but there's no shortage of pain points in ZFS. Mixing 512 byte and 4K drives or growing/shrinking pools are good starting points.

Take a look at the video/demo of the Snapper toolset built on top of btrfs. Might give you a better feel for maturity level and the tooling that it enables: http://snapper.io/

ZFS is licensed under the CDDL, while the Linux Kernel is licensed under the GPLv2.

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