Comment by happosai
The annual reminder that if Oracle wanted to contribute positively to the Linux ecosystem, they would update the CDDL license ZFS uses to GPL compatible.
The annual reminder that if Oracle wanted to contribute positively to the Linux ecosystem, they would update the CDDL license ZFS uses to GPL compatible.
Is there a reason the OpenZFS contributors don't want to dual-license their code? I'm not too familiar with the CDDL but I'm not sure what advantage it brings to an open source project compared to something like GPL? Having to deal with DKMS is one of the reasons why I'm sticking with BTRFS for doing ZFS-like stuff.
The OpenZFS code is based on the original OpenSolaris code, and the license used is the CDDL because that is what OpenSolaris used. Dual licensing that requires the current OpenSolaris copyright holder to agree. That is unlikely without writing a very big check. Further speculation is not a productive thing to do, but since I know a number of people assume that OpenSolaris copyright holder is the only one preventing this, let me preemptively say that it is not so simple. Different groups have different preferred licenses. Some groups cannot stand certain licenses. Other groups might detest the idea of dual licensing in general since it causes community fragmentation whenever contributors decide to publish changes only under 1 of the 2 licenses.
The CDDL was designed to ensure that if Sun Microsystems were acquired by a company hostile to OSS, people could still use Sun’s open source software. In particular, the CDDL has an explicit software patent grant. Some consider that to have been invaluable in preempting lawsuits from a certain company that would rather have ZFS be closed source software.
Oracle changing the license would not make a huge difference to OpenZFS.
Oracle only owns the copyright to the original Sun Microsystems code. It doesn’t apply to all ZFS implementations (probably not OracleZFS, perhaps not IllumosZFS) but in the specific case of OpenZFS the majority of the code is no longer Sun code.
Don’t forget that SunZFS was open sourced in 2005 before Oracle bought Sun Microsystems in 2009. Oracle have created their own closed source version of ZFS but outside some Oracle shops nobody uses it (some people say Oracle has stopped working on OracleZFS all together some time ago).
Considering the forks (first from Sun to the various open source implementations and later the fork from open source into Oracle's closed source version) were such a long time ago, there is not that much original code left. A lot of storage tech, or even entire storage concepts, did not exist when Sun open sourced ZFS. Various ZFS implementations developed their own support for TRIM, or Sequential Resilvering, or Zstd compression, or Persistent L2ARC, or Native ZFS Encryption, or Fusion Pools, or Allocation Classes, or dRAID, or RAIDZ expansion long after 2005. That's is why the majority of the code in OpenZFS 2 is from long after the fork from Sun code twenty years ago.
Modern OpenZFS contains new code contributions from Nexenta Systems, Delphix, Intel, iXsystems, Datto, Klara Systems and a whole bunch of other companies that have voluntarily offered their code when most of the non-Oracle ZFS implementations merged to become OpenZFS 2.0.
If you'd want to relicense OpenZFS you could get Oracle to agree for the bit under Sun copyright but for the majority of the code you'd have to get a dozen or so companies to agree to relicensing their contributions (probably not that hard) and many hundreds of individual contributors over two decades (a big task and probably not worth it).
The only thing Oracle wants to "contribute positively to" is Larry's next yacht.
Honestly the cddl being incompatible with the gpl is one of the weirder statements to come out of the fsf. It comes up every time the cddl is mentioned but no one really knows why they are incompatible, it is basically "the fsf says they are incompatible" and when really pressed, they dithered until 2016 then came up with some hand waving that the incompatibility is some minutia as to what scope each license applies to.
The whole thing smells of some FSF agenda to me. if you ship a cddl file in your gpl project it is still a gpl licensed project and the cddl file is still a cddl licensed file.
This is the annual reply that Oracle cannot change the OpenZFS license because OpenZFS contributors removed the “or any later version” part of the license from their contributions.
By the way, comments such as yours seem to assume that Oracle is somehow involved with OpenZFS. Oracle has no connection with OpenZFS outside of owning copyright on the original OpenSolaris sources and a few tiny commits their employees contributed before Oracle purchased Sun. Oracle has its own internal ZFS fork and they have zero interest in bringing it to Linux. They want people to either go on their cloud or buy this:
https://www.oracle.com/storage/nas/