ZFS on Linux?

It appears that this is in process … no, not simply the ZFS on FUSE, but a full fledged kernel subsystem.

This is interesting. ZFS is of course, the Sun file system which has had an altogether ridiculous amount of hype, while having a modest set of nice features. The Solaris and OpenSolaris was released under was not compatible with GPL, hence many people considered this OSino (Open Source in name only), as it was not legally possible to intermix the code between the largest GPL project (Linux) and the OpenSolaris code base. Likely anyone doing this would be on the wrong end of some legal action.

Which is why ZFS on FUSE was born. It provided an API that did not require the license admixture. FUSE generally works well … GlusterFS sits atop FUSE and works quite nicely (one of our favorite parallel file systems, and shipped by default on siCluster).

This development is important given the announced changes from Oracle, and the significant questions over the future of OpenSolaris. That is, if ZFS were confined to the Solaris platform, I don’t see it as increasing its market or mind share. I’d see that as a circling of wagons.

Of course, this appears to be rendered moot by the existence and development of BTRFS, which rethinks many things. ZFS is now owned by Oracle, and BTRFS is being developed by a large consortium of folks, including Chris Mason of Oracle.

If ZFS isn’t made into a compatible with Linux kernel system (FUSE or in-kernel based) with support from Oracle, then its likely not to have a long life when the other file system is stable enough for production use. Which, as of the 2.6.35 series, it might actually be. A few missing features, but not many.

If I were giving Oracle free advice (you know, worth its price), I’d suggest a license change on OpenSolaris, and a GPLing of it. This way, Solaris and OpenSolaris can take advantage of an influx of driver bits, of other development being done for Linux without pain. Because, otherwise, the relevance of OpenSolaris etc, ZFS inclusive, will continue to drop, rapidly. And this is definitely not in Oracle’s interest.

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9 thoughts on “ZFS on Linux?

  1. It should be noted that the ZPL, which is the bit that turns ZFS into an actual filesystem, is still marked as in progress. You can use zvol as (yet another) volume manager, or you can use the DMU (the real heart of the thing which Lustre also uses directly), but if you want an actual filesystem then ZFS-FUSE and btrfs are the two to look at.

  2. “hence many people considered this OSino (Open Source in name only)”

    Ignorant people, you may add…

    “If I were giving Oracle free advice (you know, worth its price), I???d suggest a license change on OpenSolaris, and a GPLing of it. This way, Solaris and OpenSolaris can take advantage of an influx of driver bits, of other development being done for Linux without pain. Because, otherwise, the relevance of OpenSolaris etc, ZFS inclusive, will continue to drop, rapidly.”

    Why? Solaris works well as it is today, why change the license? ZFS has had a large uptake by many companies developing their own storage systems and it will be LONG before BTRFS achieves ZFS’ quality for production use… Oracle has to leverage this, why give the competition (Linux) all of your crown jewel?

    Simply by not being GPL it is not less open source. Remember, Linux = Open Source, but Open Source != Linux

  3. @Phobos

    No, I don’t consider people who regard this as the case (OSino) to be “ignorant”. They have a point, and a pretty good argument. I don’t expect to see BSD components in Linux or the other way around without a redevelopment effort. We’ve seen people just copy bits back and forth irrespective of the licenses, and they were appropriately criticized for doing this. The BSD license is also not compatible with the CDDL, so no sharing of code could occur. What Sun managed to do is to grab the veneer of an open source project, without providing an enabling mechanism for end users to contribute or have ideas flow freely back and forth between the systems. So, yes, CDDL is “open source”. And, no, OpenSolaris isn’t fairing very well.

    Why should Solaris change its license? So it can leverage all the driver bits that are available for Linux. Otherwise it will have problems attracting developers as a viable platform. The market data strongly suggests the decline of Solaris/Unix in favor of more open platforms. You may choose to ignore this, but you do so at your own peril, unless you have a very limited niche/locked in market.

    ZFS has been interesting. Of this there is no doubt. A large uptake? Well … no. ZFS carries huge baggage with it. The cost of that baggage versus the benefits hasn’t worked in Sun’s favor.

    “it will be LONG before BTRFS achieves ZFS??? quality for production use???” I think these words are more a wish than a reality. ZFS itself hasn’t fully stabilized, there have been some spectacular failures over the last year. BTRFS is on a very fast evolution track, is in active testing for end users by many groups. This time next year, I believe BTRFS will be fully stable for production use. Its not just Oracle pushing it. Its Redhat, IBM, HP, Intel, …

    As for the “why give the ‘competition’ your crown jewel” … this is an interesting comment. This strongly suggests that the “crown jewel” is not open source. Which I pointed out that OSino is a more correct appellation. But Oracle has two dogs in this race. It is a heavy contributer to Linux. It has many Linux heavyweights within the company. I don’t see ZFS as being a crown jewel. Moreover, once BTRFS stabilizes enough, which it is doing very nicely now, the value of ZFS plummets as an asset. So unless its out there, as part of a GPLed and BSDed system, no, its relevance is very low going forward. And ‘jewel’ isn’t quite the appellation I would give it then. Albatross is probably more fitting.

    As for OSS != linux, yeah, well, thats obvious. So if you have an OS which is non-GPL based, you can’t exchange code with it freely. You have to go through a process of some sort. Which means, all the code (e.g. drivers, etc) that are available for that large massive OS project, are unavailable to you. And your code, which will be rapidly challenged by new OSS code, yeah … you are gonna have problems with this going forward. Moreover, your BSD competitors will likely work out a deal for multiple licensing with the BTRFS folks, so that BTRFS will show up pretty much everywhere. Then, again, what exactly it the utility of ZFS?

    Yeah, its like that. Open sourcing as a survival strategy.

  4. Sorry, but you seem to be very badly informed.

    CDDL is an Open Source license, and it’s recognized as such. GPL is not compatible with it, so you can’t distribute derivative works including a combination of both, but if it is not a CDDL/GPL derivative, you can distribute it.

    FreeBSD (and NetBSD) and Mac OS X BOTH have CDDL code in them (ZFS and DTrace in the first one, DTrace in the second one). Only Linux is isolated from all the advantages Solaris has, that’s why they are trying to catch up with Solaris, but neither BTRFS nor SystemTap are anything close to ZFS and Dtrace. There are also BSD bits in OpenSolaris, so code sharing between those UNIX works just fine.

    OpenSolaris works well in all the laptops I have tested it on, you should give it a try before talking such non-sense. It’s not like it needs Linux’ drivers so badly, it can cope with it.

    All of OpenSolaris is open source, including it’s crown jewels (ZFS, DTrace, Crossbow, and others), it’s only Linux that has a license which is not compatible with CDDL (check it yourself).

    The GPL is a viral license, not everyone must knee before it, because not everyone wants to use an open source license that restricts freedom.

    Hence, those “people considered this OSino (Open Source in name only)” are really ignorants that don’t understand what’s going on.

  5. @Phobos – Joe builds massive parallel storage systems for a living and has used and benchmarked most filesystems that are available for the major OS’s, including Solaris and ZFS, so he knows what he is talking about – including crashes due driver problems on hardware that works fine under Linux (or just not supporting the hardware as I’ve found).

    The GPL restricts your freedom to take peoples work and fold it into closed source products without having to contribute your work back into the community (as the BSD licenses permit) – but then the majority of science is built upon the same philosophy of sharing and nobody goes around calling that viral – not even Microsoft (who were the source of that loaded phrase).

    Yes the CDDL is recognised by the OSI as an open source license but I don’t think it operates in OpenSolaris’s best interests.

  6. @Phobos

    Its obvious to me that you are a partisan in these issues.

    you should give it a try before talking such non-sense.

    I have tried it, and this is why I know it is not nonsense.

    it???s only Linux that has a license which is not compatible with CDDL (check it yourself).

    … and this is … Linux’s fault that when Sun decided to “open source” Solaris, they did so in a matter that was specifically incompatible with the major open source operating system … that was, and still is, eating its lunch? Seems a rather … er … petulant … argument … dontcha think? Put another way …

    L: “Welcome Solaris to the open source world. Too bad you didn’t use a license compatible with mine, or we could have contributed to you”

    S: “Your license is incompatible with mine, not mine with yours.”

    L: “um … er … righto”

    But to go on …

    The GPL is a viral license, not everyone must knee before it, because not everyone wants to use an open source license that restricts freedom.

    Oy vey

    Hence, those ???people considered this OSino (Open Source in name only)??? are really ignorants that don???t understand what???s going on.

    I am not one for ad hominem posts or comments. Once it degenerates into this, where peoples emotions are substituted for rational thought … I dunno.

    Phobos, here are some hard realities for you. You can like them or you can pretend they aren’t there, but it doesn’t change the reality one iota.

    First, Linux has largely decimated existing and new Solaris installations (as well as many other Unixen). Customers appreciate their better control over their own OS, and can get support everywhere.

    Second, Oracle appears to be set on a path to remove Solaris from the largest volume shipper of hardware out there. Further reducing Solaris’ footprint.

    Third, Oracle appears ready to cut OpenSolaris free. I am not happy about this, as OpenSolaris was IMO better than the branded version, in terms of driver support and what not else, but it still wasn’t terribly good compared to Linux on hardware support.

    Fourth, CDDL was designed to prevent the very cross fertilization that could have saved/advanced Solaris. Sun didn’t want Linux with zfs. So it didn’t get it (directly, though it is available as a fuse file system). It also missed out on all the nice bits that Linux got that it didnt. OFED for one.

    At the end of the day, Solaris appears to be on a permanent downward augering in … its not gaining converts, its losing them, rapidly.

    GPL license for it 2 years ago could have helped it. Today, it might just be irrelevant.

    We disagree … obviously … but I am not labeling you as ignorant, which is IMO offensive. If you can’t muster a cogent argument in response then don’t post. If you can, by all means, please do respond.

    I haven’t banned people on this blog to date. I’d like to avoid doing it. Help me avoid doing it by leaving the insults out of responses.

  7. @Chris Samuel

    “Yes the CDDL is recognised by the OSI as an open source license but I don???t think it operates in OpenSolaris???s best interests.”

    The issue at hand: Joe says CDDL is not Open Source, FSF says it is. Is your comment relevant to that issue in any way I’m not getting?

    “Joe builds massive parallel storage systems for a living and has used and benchmarked most filesystems that are available for the major OS???s, including Solaris and ZFS, so he knows what he is talking about”

    In his field of experience, that doesn’t mean he knows everything.

    @Joe

    “??? and this is ??? Linux???s fault that when Sun decided to ???open source??? Solaris, they did so in a matter that was specifically incompatible with the major open source operating system ??? that was, and still is, eating its lunch? Seems a rather ??? er ??? petulant ??? argument ??? dontcha think? Put another way ???”

    It’s the Linux camp who always has attacked Sun for the license, not the other way around. It doesn’t matter what license Sun used, Linux people want Solaris’ goodies and they can’t get them, that’s why they attack in such blatant ways. They have no problem with the BSDs, because they can do (and have done so) whatever they want with BSD code, but CDDL’s and GPL’s distribution terms differ and they can’t comply with both at the same time.

    Isn’t there freedom to use whatever license you desire for your project?. Why don’t you go bother Microsoft to release Windows under a GPL-compatible license?… at least OpenSolaris is Open Source.

    “I am not one for ad hominem posts or comments. Once it degenerates into this, where peoples emotions are substituted for rational thought ??? I dunno.”

    Yes, because FUD is rational thought.

    “Fourth, CDDL was designed to prevent the very cross fertilization that could have saved/advanced Solaris. Sun didn???t want Linux with zfs. So it didn???t get it”

    Any problem with that?… So, all the world MUST use GPL so Linux can use everything?… Why?

    “We disagree ??? obviously ??? but I am not labeling you as ignorant, which is IMO offensive. If you can???t muster a cogent argument in response then don???t post. If you can, by all means, please do respond.”

    Sorry, but telling those people that consider CDDL as OSino ignorants is not an insult, it’s the truth. Ignorance is lack of knowledge, you simply don’t know. If you feel insulted by that, grow up.

    Granted, you didn’t know CDDL was an Open Source license, so educate yourself: http://www.gnu.org/licenses/license-list.html . If you are going to ban me for not agreeing with you, FUD and everything on the Linux camp, fine. But at least have the decency to check your fact before posting what you believe as pure truth, which no one holds.

  8. Not worth the time/effort to respond, as Phobos is blatantly inserting words into my keyboard and knocking them down in standard strawman fashion. And persisting in uncivil behavior. After I warned him not to call people ignorant.

    I won’t delete the thread, everyone should see this, and see what sort of behavior is not tolerated.

    Its ok to disagree. Its not okay to do so in a purposefully insulting manner. That is the hallmark of someone without a good argument that simply wants to troll.

    So I am closing this thread to further comments, and will disable phobos from posting here.

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