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Comment by vladvasiliu | Hacker News Reader

> * zfs — zfs is technically great, but binary distribution of the zfs code is tricky, because the CDDL is GPL incompatible

Building your own ZFS module is easy enough, for example on Arch with zfs-dkms.

But there's also the issue of compatibility. Sometimes kernel updates will break ZFS. Even minor ones, 6.2.13 IIRC broke it, whereas 6.2.12 was fine.

Right now, 6.3 seems to introduce major compatibility problems.

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edit: looking through the openzfs issues, I was likely thinking of 6.2.8 breaking it, where 6.2.7 was fine. Point stands, though. https://github.com/openzfs/zfs/issues/14658

Regarding 6.3 support, it apparently is merged in the master branch, but no release as of yet. https://github.com/openzfs/zfs/issues/14622

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It might help someone: nixos can be configured to always use the latest kernel version that is compatible with zfs, I believe its config.boot.zfs.package.latestCompatibleLinuxPackages .

How is the legal situation of doing that? If I had a company I wouldn't want to get in trouble with any litigious companies.

The ArchZFS project distributes binary kernel images with ZFS integrated. I don't know what the legal situation is for that.

In my case, the Arch package is more of a "recipe maker". It fetches the Linux headers and the zfs source code and compiles this for local use. As far as they are concerned, there is no distribution of the resulting artifact. IANAL, but I think if there's an issue with that, then OpenZFS is basically never usable under Linux.

Other companies distributed kernels with zfs support directly, such as Ubuntu. I don't recall there being news of them being sued over this, but maybe they managed to work something out.

archzfs does not distribute any kernel images, they only provide pre-built modules for the officially supported kernels.

IANAL.

Oracle is very litigious. However, OpenZFS has been releasing code for more than a decade. Ubuntu shipped integrated ZFS/Linux in 2016. It's certain that Oracle knows all about it and has decided that being vague is more in their interests than actually settling the matter.

On my list of potential legal worries, this is not a priority for me.

I would add to this "IANAL But" list

https://aws.amazon.com/fsx/openzfs/

So -- AWS / Amazon are certainly big enough to have reviewed the licenses and have some understanding of potential legal risks of this.

Unless you're distributing, I don't see how anybody could do anything. Personal (or company wide) use has always allowed the mixing of basically any licenses.

The worst case scenarios would be something like Ubuntu being unable to provide compiled modules, but dkms would still be fine. Or the very unlikely ZFS on Linux getting sued, but that would involve a lengthy trial that would allow you to move away from Open ZFS.

The danger is specifically to the copyright holders of Linux - the authors who have code in the kernel. If they do not defend their copyright, then it is not strong and can be broken in certain scenarios.

"Linux copyright holders in the GPL Compliance Project for Linux Developers believe that distribution of ZFS binaries is a GPL violation and infringes Linux's copyright."

Linux bundling ZFS code would bring this text against the GPL: "You may not offer or impose any terms on any Covered Software in Source Code form that alters or restricts the applicable version of [the CDDL]."

Ubuntu distributes ZFS as an out of tree module, which taints the kernel at immediately at installation. Hopefully, this is enough to prevent a great legal challenge.

https://sfconservancy.org/blog/2016/feb/25/zfs-and-linux/

Yes, distribution has legal risks. Use does not, it only has the risk that they are unable to get ZFS distributed.

Worth noting Oracle could clear it up very easily, the fact they won't is a worrying tale.

I don't think anything Oracle can do would change the usability of OpenZFS.

I'm also not positive how easily they could fix the distribution problems given OpenZFS has over a decade of work after the split, but as a whole I'm only discussing use, not distribution.

Oracle could do what they did with DTrace in 2017, and release it under the GPL in addition to the CDDL. Then the OpenZFS folks would have to track down every contributor to OpenZFS, and get their permission to re-license their contribution. Contributions from folks who refused or couldn't be found would have to be re-implemented or dropped.

It is a pain in the ass, but it has been done before.

> If they do not defend their copyright, then it is not strong and can be broken in certain scenarios.

This is not true. Copyrights (like patents) do not have to be actively defended to remain enforceable.

This is partially true of trademarks, however.

You're right that DKMS is fairly easy (at least until you enable secure boot).

> Even minor ones, 6.2.13 IIRC broke it, whereas 6.2.12 was fine.

Interesting!

It's just a shame the license has hindered adoption. Ubuntu were shipping binary ZFS modules at one point, but they have walked back from that.

> You're right that DKMS is fairly easy (at least until you enable secure boot).

Still easy. Under Arch, the kernel image isn't signed, so if you enable secure boot you need to fiddle with signing on your own. At that point, you can just sign the kernel once the module is built. Works fine for me.

> Ubuntu were shipping binary ZFS modules at one point, but they have walked back from that.

This is incorrect? Ubuntu is still shipping binary modules.

Right, but various things point to ZFS being de facto deprecated: https://www.omgubuntu.co.uk/2023/01/ubuntu-zfs-support-statu...

> various things point to ZFS being de facto deprecated

I'm not sure that's the case? Your link points to the ZFS on root install being deprecated on the desktop. I'm not sure what inference you/we can draw from that considering ZFS is a major component to LXD, and Ubuntu and Linux's sweet spot is as a server OS.

> Ubuntu were shipping binary ZFS modules at one point, but they have walked back from that.

Not to be persnickety, but this was your claim, and Ubuntu is still shipping ZFS binary modules on all it's current releases.

Yeah, my wording was clumsy, but thanks for assuming good faith. I essentially meant their enthusiasm had wained.

It's good you can give reasons ZFS is still important to Ubuntu on the server, although as a desktop user I'm sad nobody wants to ship ZFS for the desktop.

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