9 ms·

How come Linux has licensing issues with ZFS, but the BSDs don't?

mtzet 6y ago
The ZFS license (CDDL) is (arguably) incompatible with GPL. This is not a problem for FreeBSD since it’s not using GPL.
qalmakka 6y ago
Because the CDDL (by design, as inherited from the MPL 1.x) is not compatible with the GPL, due to the fact that both try to enforce their own copyleft without allowing relicensing (i.e the MPL2 avoids this thanks to a annex clause that allows you to consider everything as covered by the GPL instead). You can't cover the ZFS modules with the GPL in the final agglomerated result (i.e. kernel + module), so it's not allowed technically by the kernel license (see the difference between the LGPL and the GPL for more info). In practice no one ever questioned this in court, so who knows what the final result would be. FreeBSD uses a super weak permissive BSD license instead, so there is no conflict because it leaves whatever code you're trying to add to it alone, without trying to enforce any additional terms on it.
trasz 6y ago
The issues are caused by GPL, while BSD is, well, BSD licensed.
- IntelMiner 6y ago
  Since Linux came first (and was GPL licensed first), it's worth remembering that ZFS was intentionally made incompatible with the GPL via the "CDDL"
  - nix23 6y ago
    >ZFS was intentionally made incompatible with the GPL via the "CDDL" That was said by one lousy youtube comment without any explanation, Ubuntu has no problems with it...and i bet they have lawyers, i think it was in that vid: https://www.youtube.com/watch?v=-zRN7XLCRhc https://www.youtube.com/watch?v=-zRN7XLCRhc It's also crazy, nearly no distro has a problem shipping ultra-proprietary software (firmware), but has a big discussion about CDDL, no one wants ZFS in the Kernel tree, imagine Linus has control over it and has no clue was ZFS even is: https://linux.slashdot.org/story/20/01/19/0059251/what-linus-torvalds-gets-wrong-about-zfs https://linux.slashdot.org/story/20/01/19/0059251/what-linus...
    - toyg 6y ago
      It is however undisputable that Sun (and Oracle later) chose to write their own license for some of their opensource efforts, when there were very established alternatives already available. It's hard not to draw the conclusion that they made things awkward on purpose (i.e. to keep it away from Linux, the dominant OS in Solaris' market).
      - nix23 6y ago
        >made things awkward on purpose Maybe, some could say that the GPL2 is really awkward, but you have to know that Microsoft and Apple have their own opensource license too...big business is awkward.
      - znpy 6y ago
        There's a very interesting talk on the matter by Bryan Cantrill where he explained that the gpl was unsuitable for their scope for a number of valid reasons, including the fact that the gpl vitality would have affected indipendent hardware vendors too, iirc. And some more cases. I hope I didn't write bs, however here is the talk of you want to know more and with more details: https://youtu.be/Zpnncakrelk https://youtu.be/Zpnncakrelk (leaping the chasm from proprietary to open: a survivor's guide) As usual Bryan Cantrill is just brilliant at explaining stuff. Edit: just to be explicit: it was NOT about keeping stuff out of Linux.
        toyg 6y ago
        It's sad that even a brilliant person like Bryan can get opensource so horribly wrong at a fundamental level. Right at the beginning, he says F/OSS established itself because it leapt ahead technologically, not because "all that freedom / user rights stuff"; he totally fails to see how that "user rights stuff" is what allowed the jump to happen - because even developers are users when they first encounter a piece of software. Without the rights of users to read source, tweak it to their liking, and republish it, there is no right for developers to enable the technological leap. I hope Bryan simply chose a poor turn of phrase. He makes another poor turn when he says that the CDDL kept stuff out of Linux, but "not because of the CDDL but because of perceptions of the GPL" (i.e. IHVs didn't want to deal with the GPL). The license and the choice of using it are two different things. Sun could have written a license that was not GPL (to satisfy IHVs) but was compatible with GPL. They did not. Danese Cooper, who was part of that effort, says this was on purpose, and stated it on record ( http://caesar.ftp.acc.umu.se/pub/debian-meetings/2006/debconf6/theora-small/2006-05-14/tower/OpenSolaris_Java_and_Debian-Simon_Phipps__Alvaro_Lopez_Ortega.ogg http://caesar.ftp.acc.umu.se/pub/debian-meetings/2006/debcon... from 27:30). I guess Bryan was one of those engineers Danese mentions as "having some biases" back then. It was certainly obvious, at the time, what a careful avoidance of a license compatible with the biggest Solaris competitor would have resulted in, from a practical and commercial standpoint.
nabla9 6y ago
There is potential GPL violation. Nothing in ZFS violates BSD. GPL violation is matter of opinion. For the opinion to be settled someone owning Linux copyright should sue Canonical and find out. Canonical's did legal review and they have some big name open-source lawyers like Eben Moglen and Mishi Choudhary on their side https://www.softwarefreedom.org/resources/2016/linux-kernel-cddl.html https://www.softwarefreedom.org/resources/2016/linux-kernel-... They see it as a non-issue. So much that Canonical provides legal cover for all paying customers.
cat199 6y ago
they do. just to a lesser extent than linux, and policies vary within the family (see also: https://www.mail-archive.com/misc@openbsd.org/msg105077.html https://www.mail-archive.com/misc@openbsd.org/msg105077.html) not going to get into particulars because it's a big topic.

The ZFS license (CDDL) is (arguably) incompatible with GPL. This is not a problem for FreeBSD since it’s not using GPL.

Because the CDDL (by design, as inherited from the MPL 1.x) is not compatible with the GPL, due to the fact that both try to enforce their own copyleft without allowing relicensing (i.e the MPL2 avoids this thanks to a annex clause that allows you to consider everything as covered by the GPL instead). You can't cover the ZFS modules with the GPL in the final agglomerated result (i.e. kernel + module), so it's not allowed technically by the kernel license (see the difference between the LGPL and the GPL for more info). In practice no one ever questioned this in court, so who knows what the final result would be. FreeBSD uses a super weak permissive BSD license instead, so there is no conflict because it leaves whatever code you're trying to add to it alone, without trying to enforce any additional terms on it.

trasz 6y ago

The issues are caused by GPL, while BSD is, well, BSD licensed.

IntelMiner 6y ago
Since Linux came first (and was GPL licensed first), it's worth remembering that ZFS was intentionally made incompatible with the GPL via the "CDDL"
- nix23 6y ago
  >ZFS was intentionally made incompatible with the GPL via the "CDDL" That was said by one lousy youtube comment without any explanation, Ubuntu has no problems with it...and i bet they have lawyers, i think it was in that vid: https://www.youtube.com/watch?v=-zRN7XLCRhc https://www.youtube.com/watch?v=-zRN7XLCRhc It's also crazy, nearly no distro has a problem shipping ultra-proprietary software (firmware), but has a big discussion about CDDL, no one wants ZFS in the Kernel tree, imagine Linus has control over it and has no clue was ZFS even is: https://linux.slashdot.org/story/20/01/19/0059251/what-linus-torvalds-gets-wrong-about-zfs https://linux.slashdot.org/story/20/01/19/0059251/what-linus...
  - toyg 6y ago
    It is however undisputable that Sun (and Oracle later) chose to write their own license for some of their opensource efforts, when there were very established alternatives already available. It's hard not to draw the conclusion that they made things awkward on purpose (i.e. to keep it away from Linux, the dominant OS in Solaris' market).
    - nix23 6y ago
      >made things awkward on purpose Maybe, some could say that the GPL2 is really awkward, but you have to know that Microsoft and Apple have their own opensource license too...big business is awkward.
    - znpy 6y ago
      There's a very interesting talk on the matter by Bryan Cantrill where he explained that the gpl was unsuitable for their scope for a number of valid reasons, including the fact that the gpl vitality would have affected indipendent hardware vendors too, iirc. And some more cases. I hope I didn't write bs, however here is the talk of you want to know more and with more details: https://youtu.be/Zpnncakrelk https://youtu.be/Zpnncakrelk (leaping the chasm from proprietary to open: a survivor's guide) As usual Bryan Cantrill is just brilliant at explaining stuff. Edit: just to be explicit: it was NOT about keeping stuff out of Linux.
      - toyg 6y ago
        It's sad that even a brilliant person like Bryan can get opensource so horribly wrong at a fundamental level. Right at the beginning, he says F/OSS established itself because it leapt ahead technologically, not because "all that freedom / user rights stuff"; he totally fails to see how that "user rights stuff" is what allowed the jump to happen - because even developers are users when they first encounter a piece of software. Without the rights of users to read source, tweak it to their liking, and republish it, there is no right for developers to enable the technological leap. I hope Bryan simply chose a poor turn of phrase. He makes another poor turn when he says that the CDDL kept stuff out of Linux, but "not because of the CDDL but because of perceptions of the GPL" (i.e. IHVs didn't want to deal with the GPL). The license and the choice of using it are two different things. Sun could have written a license that was not GPL (to satisfy IHVs) but was compatible with GPL. They did not. Danese Cooper, who was part of that effort, says this was on purpose, and stated it on record ( http://caesar.ftp.acc.umu.se/pub/debian-meetings/2006/debconf6/theora-small/2006-05-14/tower/OpenSolaris_Java_and_Debian-Simon_Phipps__Alvaro_Lopez_Ortega.ogg http://caesar.ftp.acc.umu.se/pub/debian-meetings/2006/debcon... from 27:30). I guess Bryan was one of those engineers Danese mentions as "having some biases" back then. It was certainly obvious, at the time, what a careful avoidance of a license compatible with the biggest Solaris competitor would have resulted in, from a practical and commercial standpoint.

nabla9 6y ago

There is potential GPL violation. Nothing in ZFS violates BSD. GPL violation is matter of opinion. For the opinion to be settled someone owning Linux copyright should sue Canonical and find out. Canonical's did legal review and they have some big name open-source lawyers like Eben Moglen and Mishi Choudhary on their side https://www.softwarefreedom.org/resources/2016/linux-kernel-cddl.html https://www.softwarefreedom.org/resources/2016/linux-kernel-... They see it as a non-issue. So much that Canonical provides legal cover for all paying customers.

cat199 6y ago

they do. just to a lesser extent than linux, and policies vary within the family (see also: https://www.mail-archive.com/misc@openbsd.org/msg105077.html https://www.mail-archive.com/misc@openbsd.org/msg105077.html) not going to get into particulars because it's a big topic.