8 ms·

OpenZFS launch

293 points by mahrens 13y ago

crb 13y ago
Still CDDL, so still cannot be included in the main Linux kernel tree?
- mahrens 13y ago
  The legal issue is a matter of some debate (see below). In practice, I don't think the Benevolent Dictator wants ZFS in the main Linux kernel tree at the moment. http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue
  - rgbrenner 13y ago
    There's no debate. The CDDL has never been compatible with the GPL... and CDDL'd code will never be a part of the kernel. http://www.gnu.org/licenses/license-list.html#CDDL http://www.gnu.org/licenses/license-list.html#CDDL http://www.groklaw.net/articlebasic.php?story=20041205023636236 http://www.groklaw.net/articlebasic.php?story=20041205023636... http://www.groklaw.net/article.php?story=20050205022937327 http://www.groklaw.net/article.php?story=20050205022937327 In this link Linus talks about loadable module licensing.. gives an example of AFS, which he says he did not think counted as a derived work (and therefore did not need to be licensed under the GPL).. very similar to the ZFS case. https://lkml.org/lkml/2003/12/3/228 https://lkml.org/lkml/2003/12/3/228
    - mahrens 13y ago
      You don't see Linus's viewpoint as contrary to the one on gnu.org? It seems like Linus is saying that the GPL allows AFS to be used with Linux (because it is not a "derived work"). How is ZFS different from AFS in this respect?
      - rgbrenner 13y ago
        No, I don't. The gnu link says CDDL is not compatible with the GPL. What Linus is saying is, if a kernel loadable module relies on kernel internals, then it may count as a derived work, and must be licensed under a GPL-compatible license. If it does not -- for example, it is a filesystem that was ported to Linux (like AFS, and zfs fits here too IMO), then it may not be a derived work, and can be licensed under a non-gpl compatible license (like the CDDL). Obviously, including the AFS or zfs into the source WOULD DEFINITELY create a derived work, and would require AFS/ZFS to be licensed under the GPL. So Linus' is only explaining how a kernel loadable module could be licensed under a GPL-incompatible license.
        Dylan16807 13y ago
        I don't understand how putting the code into the same repository/makefile changes whether it's derivative in terms of copyright.
        mzs 13y ago
        If yo take a Makefile which say Linus had written and tack on some of your own rules, you have almost certainly (unless the original Makefile was something trivial like ::) created a derived work.
        raimue 13y ago
        If you distribute a single source tarball with code files with different licenses, all of them apply. There may be different terms limiting what you are allowed to do with the file in each of the licenses, while the most restrictive license terms apply to the whole file. Besides the real legal issues, this also causes unnecessary confusion for users and those creating packages for binary distribution. Therefore, using multiple incompatible licenses in a single source tree is usually avoided.
        Dylan16807 13y ago
        >If you distribute a single source tarball with code files with different licenses, all of them apply. Yes, the tarball distribution must respect all the licenses of files inside it, but once the tarball is unpacked it goes back to individual licenses per file. I understand how it's a big mess when it gets to binaries, but do any licenses actually place restrictions on what they can be tarballed with?
    - rgbrenner 13y ago
      Here's a much better link.. someone collected various emails from Linus on loadable modules: http://linuxmafia.com/faq/Kernel/proprietary-kernel-modules.html http://linuxmafia.com/faq/Kernel/proprietary-kernel-modules....
  - SEJeff 13y ago
    Lets forget the licensing entirely. ZFS was built ontop of the Solaris VFS layer (virtual file system), which is entirely different than the Linux VFS. Taking the code in the Solaris kernel that provides ZFS and porting it to the Linux VFS is a massive undertaking that would require rewriting most of the "stable" guts of ZFS. Honestly other than the fuse stuff, I doubt ZFS will ever be in Linux as it would require a rewrite of such a large portion of code, it would be impractical.
    - insaneirish 13y ago
      > Taking the code in the Solaris kernel that provides ZFS and porting it to the Linux VFS is a massive undertaking that would require rewriting most of the "stable" guts of ZFS. And it's been done and working quite well considering. There still are improvements to be made, but progress is happening. See slide 9 of this in particular: http://www.slideshare.net/MatthewAhrens/open-zfs-linuxcon http://www.slideshare.net/MatthewAhrens/open-zfs-linuxcon
      - SEJeff 13y ago
        I don't mean adding solaris / illumos interfaces (see slide 8 on your link) into the Linux kernel. That will simply never be accepted upstream. I mean properly porting it from the Solaris to the Linux VFS without a shim ie a native port. That still has not been done. It is a ridiculous amount of work.
        kinghajj 13y ago
        Wait, if the current Linux ZFS module doesn't interface with the Linux VFS, then how does the filesystem even work? Did they write a Solaris VFS -> Linux VFS bridge?
        SEJeff 13y ago
        Yes, as evidenced on slide 8 of that link. """ Solaris Porting Layer - Adds stable Solaris/Illumos interfaces * Tasqs, lists, condition variables, rwlocks, memory allocators, etc - Layers ontop of Linux equivalents if available - Solaris specific interfaces were implemented from scratch """ It doesn't (currently) use the Linux page cache, which causes quite a few ancillary issues. The idea is awesome, but this will simply never be able to be "natively" in linux without a rewrite of much of the core.
shmerl 13y ago
Are they going to reconcile incompatibilities with GPL by adding additional license? Since OpenZFS is not associated with Oracle, who owns it (as in giving it a new / additional license?). It's a really silly situation since according to the authors they never intended to use the license to exclude Linux. But that's what happened.
- vertex-four 13y ago
  Unfortunately, Sun (now Oracle) provided the original source code under the CDDL, so re-licensing it would require Oracle's approval, which is unlikely to happen. ZFS's license is compatible with those of FreeBSD and Illumos, which are very stable operating systems. Given that ZFS is most likely to be used for a SAN or a NAS box, you can quite easily use FreeBSD for those boxes and Linux for your application servers if you choose.
  - shmerl 13y ago
    So essentially Oracle still owns the original rights on it? How does it work with derivatives? Let's say OpenZFS over the years will move far away from Oracle's ZFS. Will it sill be indirectly controlled by them as in not allowing to relicense it?
    - lambada 13y ago
      Generally it's a complicated area. Generally the only safe way to sneak out from under an existing license would be a black-box rewrite, done by people who hadn't looked at the source for the original version. Otherwise the original author could claim that it's a derivative work, and thus falls under the terms of the original license. The CDDL in particular specifies that any modifications (changes, additions or deletions to the source code or their files) are also under the CDDL. See http://web.archive.org/web/20090305064954/http://www.sun.com/cddl/cddl.html http://web.archive.org/web/20090305064954/http://www.sun.com... 3.2,3.4 along with their definition of Modification. However, even a black-box rewrite could still fall foul of any patents granted to the original creators.
matt_heimer 13y ago
Not GPL compatible and patents from my understanding. Is there any way they can expect large scale deployments or linux integration?
- mahrens 13y ago
  ZFS on Linux large scale deployments: 55 Petabytes at LLNL http://www.slideshare.net/MatthewAhrens/open-zfs-linuxcon http://www.slideshare.net/MatthewAhrens/open-zfs-linuxcon See slide 3; last slide has a little more detail. ZFS on illumos: Nexenta claims 1.5 Exabytes under management (across multiple deployments) http://billroth.ulitzer.com/node/2461630 http://billroth.ulitzer.com/node/2461630
- mook 13y ago
  FWIW, my understanding is that CDDL, as a MPL-derived license, had a patent licensing clause and therefore the patents don't matter as long as it's using that set of source code. So a clean room rewrite might run afoul of patents, but the existing CDDL licensed code is okay. (See CDDL, section 2.1(b), but keep in mind section 2.1(d) where modifications and deleted code are not covered.)
VikingCoder 13y ago
Can I please, please, please have a Windows port? At work, we use Windows boxes, and I would love to use ZFS on them.
- astrodust 13y ago
  The operating systems that are getting support are mostly or at least partly open-source, so good luck with that.
  - Demiurge 13y ago
    That's probably not as big of a detriment as the high level functionality Windows expects to be in the filesystem layer that unix doesn't (or puts in VFS). From what I read, this is why Microsoft themselves have a hard time replacing NTFS.
    - VikingCoder 13y ago
      There's having ZFS running as a native Windows file system... ...and then there's running ZFS on my Windows systems, which I must use a special API to access. The second one isn't ideal, but it would be awesome to have.
- Elhana 13y ago
  There is http://code.google.com/p/zfs-win/ http://code.google.com/p/zfs-win/ ,but it is not really useful.
- gtirloni 13y ago
  You might be surprised at what WinServer 2012 already supports in that area: http://www.microsoft.com/en-us/server-cloud/windows-server/storage-features.aspx http://www.microsoft.com/en-us/server-cloud/windows-server/s...
  - VikingCoder 13y ago
    You might be surprised that if you pay more money, Microsoft has more to sell you. No, I'm not. I like FOSS, and ZFS seems excellent - I wish it made it to Windows. Like, Windows 7, for consumers and businesses...
patrickg_zill 13y ago
ZFS is really a good thing, even if you never use it. Why? It raised the bar on filesystems and other filesystems have innovated in response.
- craigyk 13y ago
  years later, I'm still waiting for the supposedly better algorithmic underpinning of btrfs to pay off. I also understand the conceptual benefits of technology layering as done in linux (RAID, and/or LVM, FS), but ZFS's vertical integration and monolithic set off tools are SO nice and consistent.
  - spetsnaz 13y ago
    Yup, what happened with butter fs?? It was supposed to be better than zfs, wasn't it?
    - craigyk 13y ago
      It exists and it's pretty good so far, but it's still far from the functionality and polish of ZFS.
- VLM 13y ago
  I would tentatively disagree with raising the bar and describe it using my favorite MySQL / PostGRES analogy that they have a fundamentally different philosophy but do about the same thing. For example, if you want to do something software raid-ish, ZFS has the philosophy that should be done at the filesystem layer, not as a virtual device like every other linux filesystem, ever. Its not a new feature to be able to do RAID, but its new to embed RAID into the filesystem layer itself. Linux style virtual RAID devices don't care if you build a FAT32 on top of /dev/md0. There are other examples of the same philosophy in ZFS. For example everywhere else in linux if you want some manner of "volume manager" you simply use LVM. ZFS has its own interesting little volume manager. Which relates to snapshots. It's exactly the same with encryption. Every other implementation on linux uses a loop device and your choice of algo. ZFS shoves all that inside the filesystem. Another philosophical decision is every other linux filesystem doesn't scrub, but only fsck's metadata, so logically ZFS implements the exact opposite. Although ZFS supporters are technically telling the truth when they run around saying only ZFS can provide software RAID, or only ZFS has a volume manager, and ext2/3/4 does not, its not relevant. I've had LVM and software RAID and all that for many years on existing linux stuff. One of the few true features ZFS provides is allowing ridiculously big filesystems. Which is cool. It is mostly a philosophical difference between modularity and monolithic design, with pretty much everything else being modular, and ZFS being extremely monolithic. In that way I don't think ZFS has prodded any innovation at all in any other filesystems other than maybe BTRS which I haven't been following because my data is too valuable to experiment upon and filesystems aren't my thing. I don't see the iso9660 FS driver adding native volume management, snapshotting, software RAID, and encryption any time soon.
r00fus 13y ago
What about patent encumbrance? Has the squabble between Sun(now Oracle) and NetApp been completely resolved? According to this[1], it was a quiet draw-down, followed by NetApp suing some hardware manufacturers selling ZFS. Are the patent issue laid to rest? [1] http://en.swpat.org/wiki/NetApp's_filesystem_patents http://en.swpat.org/wiki/NetApp's_filesystem_patents
- BrainInAJar 13y ago
  CDDL has patent shielding. Oracle is on the hook for that patent, not users of Sun's (now Oracle's) CDDL licensed code.
emillon 13y ago
I have trouble understanding the position of OpenZFS. My understanding is that Oracle ZFS, which can not be integrated in mainline Linux, can still be distributed as a separate project (zfsonlinux.org). On the other hand, Linux kernel developers have started btrfs, which is inspired by, but incompatible with, ZFS. So, what is this project? I can only imagine that this is either a white room reimplementation of ZFS, or a fork before the license changed (but I think it was CDDL from the start). A more interesting question would be: who should use or develop this? IMHO this will never be on par with "the" ZFS, so btrfs is where everyone's energy should go. (Also, by reimplementing a ZFS product you're supporting them in a way.)
- dkl 13y ago
  And aren't there a bunch of newer ZFS features that Oracle has implemented that are not OSS? So, those are known only in documentation?
  - cdjk 13y ago
    ZFS has the notion of version numbers - for both the zpool and filesystem. The last FOSS releases are zpool 28 and zfs 5. There have been subsequent releases of ZFS by Oracle, but versions 28 and 5 are the latest used by all the open source implementations. What the FOSS community has done is to add "feature flags" to ZFS instead of constantly bumping the version number. So encryption is a feature on top of zfs, but the encryption introduced in FreeNAS for ZFS isn't the same as the encryption in Oracle's zpool v30.
    - finnh 13y ago
      I'm glad to see open-zfs.org for exactly the reasons you mention. I've been runnning MacZFS for years, but it's currently way behind at zpool version 8, zfs version 2. At one point I put a FreeBSD machine in the basement, with plans to stream snapshot diffs for backup, but the version mismatches prevented me from doing this in a smart (zfs-based, rather than rsync-based) way. Looks like this central coordination point ought to help the porting of features/versions from the Linux branch to the Mac branch.
dkl 13y ago
How does this and ZFS on Linux compare? How are they related? As a casual bystander, this is all very confusing.
- shmerl 13y ago
  See http://zfsonlinux.org http://zfsonlinux.org
- jdboyd 13y ago
  ZFS on Linux is OpenZFS ported to Linux. As various OpenZFS users (FreeBSD, Nexenta, etc) add features to OpenZFS the code will be merged upstream then adopted downstream by the other OpenZFS users (including ZFS on Linux).
cs702 13y ago
I suspect an unmentioned goal of this project is eventually to make the installation of OpenZFS on Linux (and other *ix operating systems) quick and simple, legally running around Oracle's license restrictions.[1] Unsurprisingly, the list of supporting companies[2] does not include Oracle, which surely isn't happy about this project. -- [1] The source code upon which OpenZFS is based was provided by Oracle (Sun) under the CDDL license, which prevents OpenZFS from being distributed in binary form as part of the Linux kernel. [2] http://www.open-zfs.org/wiki/Companies http://www.open-zfs.org/wiki/Companies
- synchronise 13y ago
  Nothing stopping you from writing a script that automatically compiles and installs the module when you're installing your distro.
  - patrickg_zill 13y ago
    I think the Debian install is almost as easy as that - download a .deb package and install it, and it pulls in and installs and compiles everything else.
  - ed_blackburn 13y ago
    Homebrew?
  - saosebastiao 13y ago
    There are lots of things stopping me from doing that. Like ensuring I don't break everything I touch. Not everybody is a sysadmin.
- gonzo 13y ago
  You can already install on ZFS in FreeBSD.
  - laumars 13y ago
    It's a great pity more ZFS advocates are taking this as an opportunity to get better acquainted with FreeBSD. I've been running FreeBSD on my home server for about a decade now -even before ZFS- and have loved it. But I used to run Linux VMs on top of it. However it's only recently that I've decided to go fully FreeBSD on it, using jails instead of hardware virtualisation. I honestly can't understand why I waited so long to do so. It's proven to be a far more elegant solution for what I needed. While I do still run Linux on my desktop and work with Solaris and linux as my day job; FreeBSD seems a vastly overlooked alternative these days, which I think that's a great pity. its stable, proven and dead to administrate. But each to their own I guess.
oscargrouch 13y ago
you know why this is huge? its the first kernel piece of code that are and can be shared by different open-source operating systems in the kernel codebase! i hope more technologies could get up into this model.. while the democratic open-source ecosystem in userland is a rule this days.. on the kernel land this is not true and that may force us to use a OS instead of other because of some feature that only that Os has, even if we wish to install the other one.. for instance, i love linux, but i also love the BSD´s and want them to grow as much as linux did.. if the good things created in one OS could also be used on other, by a proper port to that kernel, we might not being bullied to accept on OS in favor of another, and be stuck by it! I hope this movement make its way to others kerneland technologies! great news!
- simcop2387 13y ago
  Not quite the first, but likely to end up one of the most wide spread. The DRM graphics drivers are actually older than ZFS and have been MIT licensed from the beginning (they started from older MIT licensed X11 projects). There's also possibly some other's from the BSD projects (network drivers and such) that are even older than those.
  - oscargrouch 13y ago
    yeah, but in those cases you have cited, the interested party get the source and implements it on its own codebase himself eg. microsoft using bsd network layer on windows and freebsd porting linux drm to its own kernel.. this is different.. its aggregated as a product that target several os´s with different implementations for each kernel, but shareing only one core codebase.. this tends to be much more stable and cheap to everybody.. less bug prone, etc.. didnt heard of anything like it..
tete 13y ago
I am curious. What are you using ZFS for?
- contingencies 13y ago
  https://en.wikipedia.org/wiki/Comparison_of_filesystems#Features https://en.wikipedia.org/wiki/Comparison_of_filesystems#Feat...
  - tete 13y ago
    I know. I mostly ask, because a lot of people these days keep nearly every kind of data in databases and ZFS usually isn't the best thing for this (depending on the exact use case of course). It's by far one of the most exciting file systems, for storing "raw" data, but if you are having another layer, your data base system it (again, based on the exact use case) can become an unbearable overhead performancewise.
- Sanddancer 13y ago
  I'm personally using it on my set of freebsd jailed boxes to provide quota-ing in a useful way, de-duplication of shared files in those quotaed trees, compression of things like the ports tree, etc. Subvolumes are sexy as hell in how you can have one filesystem, but give lots of different attributes to various bits and pieces.
deleted 13y ago
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fsckin 13y ago
I built a 16TB raidz home office server this weekend using Ubuntu and ZFS on Linux[0]. It worked great out of the box. I was even able to import a pool created on another server without any problem. Of course, your mileage may vary. I was using FreeNAS previously (mainly for the ZFS support to keep my data safe and not spend a bunch on raid controllers) and kept getting bogged down by feeling the need to grok jails. I think jails are terrific in theory, but a pain to work with if you're not intimately familiar with them. Maybe it's just the way it works on FreeNAS, but newly created jails (by default on FreeNAS) were getting a new virtual IP addresses, which really threw me for a loop. Add to that frustration trying to get all the permissions correct just to make a few different services work together started to get really painful. The drop-dead simplicity of setting up exactly what I had previously on a fresh Ubuntu box with native ZFS port really warmed my cockles. [0] http://zfsonlinux.org/ http://zfsonlinux.org/
- mikevm 13y ago
  What's the advantage of using ZFS RAIDZ over mdadm? I thought that mdadm was more flexible in growing your RAID array.
  - KaiserPro 13y ago
    The documentation for raidZ is wonderful, and the commands are logical. mdam is a pain, and doesn't provide block level checksums, so you can easily get silent corruption.
  - cdjk 13y ago
    I think the primary advantage is that ZFS collapses all the standard filesystem abstractions. With mdadm or hardware raid you have a raid controller (which could be mdadm), volume manager (i.e. lvm), and filesystem (ext4, xfs, etc). ZFS combines all of that into one. It's really a different philosophy, but means that things like creating a new filesystem is almost instant (and CoW, snapshots, replication are all easy - although perhaps that's possible with the traditional abstractions as well).
  - craigyk 13y ago
    I think the RAIDZ is also less susceptible to data loss due to the RAID layer and the filesystem being tightly integrated.
deleted 13y ago
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acd 13y ago
ZFS is the best thing that happened in storage! Big thanks to the developers! Happily uses Western Digital 25AV 2.5 disks. Will probably use WD Red series. Total remote backup time with ZFS incremental snapshots negligible.
magg 13y ago
the site is lacking the Mac OS X version called Zevo: http://getgreenbytes.com/solutions/zevo/ http://getgreenbytes.com/solutions/zevo/. It was developed by Don Brady, formerly a Senior Software Engineer at Apple
- adsr 13y ago
  And it's at Zpool 28 already.
cmccabe 13y ago
I have a lot of respect for those working on this project, but realistically, if you use Linux, using an out-of-tree filesystem is just asking for pain-- lots of it. I would never use this on a production system. You know how painful out-of-tree video drivers are? Yeah. Imagine that, only now with the potential for data loss and divergent on-disk formats. And if it's your root fs, you can forget about booting if there's a problem. Sure ZFS has a great reputation, but a lot of that came from how well-integrated it was into Solaris and how much QA was done on it. Neither of those things were ever true (or are going to be true in the future) for the various ZFS-on-Linux projects (yes, there are multiple.) The comments about btrfs are about 5 years out of date. SuSE has already shipped btrfs in their "stable" 11.1 distribution, and Red Hat is going to do so in RHEL7. Give it a chance.
- cbsmith 13y ago
  > The comments about btrfs are about 5 years out of date. Not really. I've tried it, and it still has pain points I'd not like to have in my filesystem. It's like ZFS almost a decade ago (and I'm not talking about features)... although ZFS on Linux vs. btrfs on Linux... right now I'd still go with btrfs. > Neither of those things were ever true (or are going to be true in the future) for the various ZFS-on-Linux projects (yes, there are multiple.) I believe there is a shift with regard to this, as demonstrated by the Gentoo project's integration of ZFS.
  - unhammer 13y ago
    > Not really. I've tried it, and it still has pain points I'd not like to have in my filesystem. It's like ZFS almost a decade ago (and I'm not talking about features)... although ZFS on Linux vs. btrfs on Linux... right now I'd still go with btrfs. Care to elaborate? I've never tried ZFS, but been very happy with btrfs for my smalltime personal usage, I'm wondering why people find it so painful in comparison.
    - cbsmith 13y ago
      Well, there's just the general lack luster performance: http://www.phoronix.com/scan.php?page=article&item=linux_311_filesystems&num=3 http://www.phoronix.com/scan.php?page=article&item=linux_311... I've also seen particularly bad pain points when doing things like using it with an NFS server.
contingencies 13y ago
I dabbled in ZFS on FreeBSD + OpenSolaris 3 years back. It was nice and all, but it hasn't been worth the overhead of running another OS to get its features since. I'm therefore glad to see some unity in the ZFS community to create more trust around its use in Linux, and proud to see my beloved Gentoo in the list of standard-bearers! Bring on the unrivalled pragmatism. Quack quack. Observation: Gentoo packages still point to http://zfsonlinux.org/ http://zfsonlinux.org/ not to http://open-zfs.org/ http://open-zfs.org/ .. is this the same code? I suppose so. Further observation: The kernel code looks like, as packaged by Gentoo, it can only be compiled as a module. Generally I disable LKMs on production systems. Grumble.
- dmpk2k 13y ago
  it hasn't been worth the overhead of running another OS to get its features since. That's a rather cavalier attitude towards the integrity of your data. :/ I can replace operating systems. It's a lot more difficult to replace lost or silently-corrupted data. That makes data integrity one of my prime concerns, which it should be for any production systems.
  - contingencies 13y ago
    That's a rather cavalier attitude towards the integrity of your data ... data integrity one of my prime concerns, which it should be for any production systems. Different projects have different resources and requirements. There's far more ways than just ZFS to provide for data redundancy and integrity (TMTOWTDI). (Edit: why the downvote? Geez.)
    - dmpk2k 13y ago
      Downvote wasn't me. I agree with the sentiment regarding requirements. However, I disagree with the bit regarding data redundancy and integrity. You can do it other ways, but that doesn't make it a good idea; it's a bit like Greenspun's Tenth Rule, but for data. ZFS, or something like it (and there isn't anything else like it), is the foundation of any modern setup where data is important. Because it's not on Linux is a terrible reason. If your data is important, then you'll need to look elsewhere than Linux for the servers where the data sleeps. The importance of data requires it. If data is relatively unimportant, then you're right. There are few domains where that's true nowadays though.
phryk 13y ago
FORK YEAH, this is what I've been waiting for the last 2 or so years. <3

OpenZFS launch

293 points by mahrens 13y ago

crb 13y ago

Still CDDL, so still cannot be included in the main Linux kernel tree?

mahrens 13y ago
The legal issue is a matter of some debate (see below). In practice, I don't think the Benevolent Dictator wants ZFS in the main Linux kernel tree at the moment. http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue
- rgbrenner 13y ago
  There's no debate. The CDDL has never been compatible with the GPL... and CDDL'd code will never be a part of the kernel. http://www.gnu.org/licenses/license-list.html#CDDL http://www.gnu.org/licenses/license-list.html#CDDL http://www.groklaw.net/articlebasic.php?story=20041205023636236 http://www.groklaw.net/articlebasic.php?story=20041205023636... http://www.groklaw.net/article.php?story=20050205022937327 http://www.groklaw.net/article.php?story=20050205022937327 In this link Linus talks about loadable module licensing.. gives an example of AFS, which he says he did not think counted as a derived work (and therefore did not need to be licensed under the GPL).. very similar to the ZFS case. https://lkml.org/lkml/2003/12/3/228 https://lkml.org/lkml/2003/12/3/228
  - mahrens 13y ago
    You don't see Linus's viewpoint as contrary to the one on gnu.org? It seems like Linus is saying that the GPL allows AFS to be used with Linux (because it is not a "derived work"). How is ZFS different from AFS in this respect?
    - rgbrenner 13y ago
      No, I don't. The gnu link says CDDL is not compatible with the GPL. What Linus is saying is, if a kernel loadable module relies on kernel internals, then it may count as a derived work, and must be licensed under a GPL-compatible license. If it does not -- for example, it is a filesystem that was ported to Linux (like AFS, and zfs fits here too IMO), then it may not be a derived work, and can be licensed under a non-gpl compatible license (like the CDDL). Obviously, including the AFS or zfs into the source WOULD DEFINITELY create a derived work, and would require AFS/ZFS to be licensed under the GPL. So Linus' is only explaining how a kernel loadable module could be licensed under a GPL-incompatible license.
      - Dylan16807 13y ago
        I don't understand how putting the code into the same repository/makefile changes whether it's derivative in terms of copyright.
        mzs 13y ago
        If yo take a Makefile which say Linus had written and tack on some of your own rules, you have almost certainly (unless the original Makefile was something trivial like ::) created a derived work.
        raimue 13y ago
        If you distribute a single source tarball with code files with different licenses, all of them apply. There may be different terms limiting what you are allowed to do with the file in each of the licenses, while the most restrictive license terms apply to the whole file. Besides the real legal issues, this also causes unnecessary confusion for users and those creating packages for binary distribution. Therefore, using multiple incompatible licenses in a single source tree is usually avoided.
        Dylan16807 13y ago
        >If you distribute a single source tarball with code files with different licenses, all of them apply. Yes, the tarball distribution must respect all the licenses of files inside it, but once the tarball is unpacked it goes back to individual licenses per file. I understand how it's a big mess when it gets to binaries, but do any licenses actually place restrictions on what they can be tarballed with?
  - rgbrenner 13y ago
    Here's a much better link.. someone collected various emails from Linus on loadable modules: http://linuxmafia.com/faq/Kernel/proprietary-kernel-modules.html http://linuxmafia.com/faq/Kernel/proprietary-kernel-modules....
- SEJeff 13y ago
  Lets forget the licensing entirely. ZFS was built ontop of the Solaris VFS layer (virtual file system), which is entirely different than the Linux VFS. Taking the code in the Solaris kernel that provides ZFS and porting it to the Linux VFS is a massive undertaking that would require rewriting most of the "stable" guts of ZFS. Honestly other than the fuse stuff, I doubt ZFS will ever be in Linux as it would require a rewrite of such a large portion of code, it would be impractical.
  - insaneirish 13y ago
    > Taking the code in the Solaris kernel that provides ZFS and porting it to the Linux VFS is a massive undertaking that would require rewriting most of the "stable" guts of ZFS. And it's been done and working quite well considering. There still are improvements to be made, but progress is happening. See slide 9 of this in particular: http://www.slideshare.net/MatthewAhrens/open-zfs-linuxcon http://www.slideshare.net/MatthewAhrens/open-zfs-linuxcon
    - SEJeff 13y ago
      I don't mean adding solaris / illumos interfaces (see slide 8 on your link) into the Linux kernel. That will simply never be accepted upstream. I mean properly porting it from the Solaris to the Linux VFS without a shim ie a native port. That still has not been done. It is a ridiculous amount of work.
      - kinghajj 13y ago
        Wait, if the current Linux ZFS module doesn't interface with the Linux VFS, then how does the filesystem even work? Did they write a Solaris VFS -> Linux VFS bridge?
        SEJeff 13y ago
        Yes, as evidenced on slide 8 of that link. """ Solaris Porting Layer - Adds stable Solaris/Illumos interfaces * Tasqs, lists, condition variables, rwlocks, memory allocators, etc - Layers ontop of Linux equivalents if available - Solaris specific interfaces were implemented from scratch """ It doesn't (currently) use the Linux page cache, which causes quite a few ancillary issues. The idea is awesome, but this will simply never be able to be "natively" in linux without a rewrite of much of the core.

shmerl 13y ago

Are they going to reconcile incompatibilities with GPL by adding additional license? Since OpenZFS is not associated with Oracle, who owns it (as in giving it a new / additional license?). It's a really silly situation since according to the authors they never intended to use the license to exclude Linux. But that's what happened.

vertex-four 13y ago
Unfortunately, Sun (now Oracle) provided the original source code under the CDDL, so re-licensing it would require Oracle's approval, which is unlikely to happen. ZFS's license is compatible with those of FreeBSD and Illumos, which are very stable operating systems. Given that ZFS is most likely to be used for a SAN or a NAS box, you can quite easily use FreeBSD for those boxes and Linux for your application servers if you choose.
- shmerl 13y ago
  So essentially Oracle still owns the original rights on it? How does it work with derivatives? Let's say OpenZFS over the years will move far away from Oracle's ZFS. Will it sill be indirectly controlled by them as in not allowing to relicense it?
  - lambada 13y ago
    Generally it's a complicated area. Generally the only safe way to sneak out from under an existing license would be a black-box rewrite, done by people who hadn't looked at the source for the original version. Otherwise the original author could claim that it's a derivative work, and thus falls under the terms of the original license. The CDDL in particular specifies that any modifications (changes, additions or deletions to the source code or their files) are also under the CDDL. See http://web.archive.org/web/20090305064954/http://www.sun.com/cddl/cddl.html http://web.archive.org/web/20090305064954/http://www.sun.com... 3.2,3.4 along with their definition of Modification. However, even a black-box rewrite could still fall foul of any patents granted to the original creators.

matt_heimer 13y ago

Not GPL compatible and patents from my understanding. Is there any way they can expect large scale deployments or linux integration?

mahrens 13y ago
ZFS on Linux large scale deployments: 55 Petabytes at LLNL http://www.slideshare.net/MatthewAhrens/open-zfs-linuxcon http://www.slideshare.net/MatthewAhrens/open-zfs-linuxcon See slide 3; last slide has a little more detail. ZFS on illumos: Nexenta claims 1.5 Exabytes under management (across multiple deployments) http://billroth.ulitzer.com/node/2461630 http://billroth.ulitzer.com/node/2461630
mook 13y ago
FWIW, my understanding is that CDDL, as a MPL-derived license, had a patent licensing clause and therefore the patents don't matter as long as it's using that set of source code. So a clean room rewrite might run afoul of patents, but the existing CDDL licensed code is okay. (See CDDL, section 2.1(b), but keep in mind section 2.1(d) where modifications and deleted code are not covered.)

VikingCoder 13y ago

Can I please, please, please have a Windows port? At work, we use Windows boxes, and I would love to use ZFS on them.

astrodust 13y ago
The operating systems that are getting support are mostly or at least partly open-source, so good luck with that.
- Demiurge 13y ago
  That's probably not as big of a detriment as the high level functionality Windows expects to be in the filesystem layer that unix doesn't (or puts in VFS). From what I read, this is why Microsoft themselves have a hard time replacing NTFS.
  - VikingCoder 13y ago
    There's having ZFS running as a native Windows file system... ...and then there's running ZFS on my Windows systems, which I must use a special API to access. The second one isn't ideal, but it would be awesome to have.
Elhana 13y ago
There is http://code.google.com/p/zfs-win/ http://code.google.com/p/zfs-win/ ,but it is not really useful.
gtirloni 13y ago
You might be surprised at what WinServer 2012 already supports in that area: http://www.microsoft.com/en-us/server-cloud/windows-server/storage-features.aspx http://www.microsoft.com/en-us/server-cloud/windows-server/s...
- VikingCoder 13y ago
  You might be surprised that if you pay more money, Microsoft has more to sell you. No, I'm not. I like FOSS, and ZFS seems excellent - I wish it made it to Windows. Like, Windows 7, for consumers and businesses...

patrickg_zill 13y ago

ZFS is really a good thing, even if you never use it. Why? It raised the bar on filesystems and other filesystems have innovated in response.

craigyk 13y ago
years later, I'm still waiting for the supposedly better algorithmic underpinning of btrfs to pay off. I also understand the conceptual benefits of technology layering as done in linux (RAID, and/or LVM, FS), but ZFS's vertical integration and monolithic set off tools are SO nice and consistent.
- spetsnaz 13y ago
  Yup, what happened with butter fs?? It was supposed to be better than zfs, wasn't it?
  - craigyk 13y ago
    It exists and it's pretty good so far, but it's still far from the functionality and polish of ZFS.
VLM 13y ago
I would tentatively disagree with raising the bar and describe it using my favorite MySQL / PostGRES analogy that they have a fundamentally different philosophy but do about the same thing. For example, if you want to do something software raid-ish, ZFS has the philosophy that should be done at the filesystem layer, not as a virtual device like every other linux filesystem, ever. Its not a new feature to be able to do RAID, but its new to embed RAID into the filesystem layer itself. Linux style virtual RAID devices don't care if you build a FAT32 on top of /dev/md0. There are other examples of the same philosophy in ZFS. For example everywhere else in linux if you want some manner of "volume manager" you simply use LVM. ZFS has its own interesting little volume manager. Which relates to snapshots. It's exactly the same with encryption. Every other implementation on linux uses a loop device and your choice of algo. ZFS shoves all that inside the filesystem. Another philosophical decision is every other linux filesystem doesn't scrub, but only fsck's metadata, so logically ZFS implements the exact opposite. Although ZFS supporters are technically telling the truth when they run around saying only ZFS can provide software RAID, or only ZFS has a volume manager, and ext2/3/4 does not, its not relevant. I've had LVM and software RAID and all that for many years on existing linux stuff. One of the few true features ZFS provides is allowing ridiculously big filesystems. Which is cool. It is mostly a philosophical difference between modularity and monolithic design, with pretty much everything else being modular, and ZFS being extremely monolithic. In that way I don't think ZFS has prodded any innovation at all in any other filesystems other than maybe BTRS which I haven't been following because my data is too valuable to experiment upon and filesystems aren't my thing. I don't see the iso9660 FS driver adding native volume management, snapshotting, software RAID, and encryption any time soon.

r00fus 13y ago

What about patent encumbrance? Has the squabble between Sun(now Oracle) and NetApp been completely resolved? According to this[1], it was a quiet draw-down, followed by NetApp suing some hardware manufacturers selling ZFS. Are the patent issue laid to rest? [1] http://en.swpat.org/wiki/NetApp's_filesystem_patents http://en.swpat.org/wiki/NetApp's_filesystem_patents

BrainInAJar 13y ago
CDDL has patent shielding. Oracle is on the hook for that patent, not users of Sun's (now Oracle's) CDDL licensed code.

emillon 13y ago

I have trouble understanding the position of OpenZFS. My understanding is that Oracle ZFS, which can not be integrated in mainline Linux, can still be distributed as a separate project (zfsonlinux.org). On the other hand, Linux kernel developers have started btrfs, which is inspired by, but incompatible with, ZFS. So, what is this project? I can only imagine that this is either a white room reimplementation of ZFS, or a fork before the license changed (but I think it was CDDL from the start). A more interesting question would be: who should use or develop this? IMHO this will never be on par with "the" ZFS, so btrfs is where everyone's energy should go. (Also, by reimplementing a ZFS product you're supporting them in a way.)

dkl 13y ago
And aren't there a bunch of newer ZFS features that Oracle has implemented that are not OSS? So, those are known only in documentation?
- cdjk 13y ago
  ZFS has the notion of version numbers - for both the zpool and filesystem. The last FOSS releases are zpool 28 and zfs 5. There have been subsequent releases of ZFS by Oracle, but versions 28 and 5 are the latest used by all the open source implementations. What the FOSS community has done is to add "feature flags" to ZFS instead of constantly bumping the version number. So encryption is a feature on top of zfs, but the encryption introduced in FreeNAS for ZFS isn't the same as the encryption in Oracle's zpool v30.
  - finnh 13y ago
    I'm glad to see open-zfs.org for exactly the reasons you mention. I've been runnning MacZFS for years, but it's currently way behind at zpool version 8, zfs version 2. At one point I put a FreeBSD machine in the basement, with plans to stream snapshot diffs for backup, but the version mismatches prevented me from doing this in a smart (zfs-based, rather than rsync-based) way. Looks like this central coordination point ought to help the porting of features/versions from the Linux branch to the Mac branch.

dkl 13y ago

How does this and ZFS on Linux compare? How are they related? As a casual bystander, this is all very confusing.

shmerl 13y ago
See http://zfsonlinux.org http://zfsonlinux.org
jdboyd 13y ago
ZFS on Linux is OpenZFS ported to Linux. As various OpenZFS users (FreeBSD, Nexenta, etc) add features to OpenZFS the code will be merged upstream then adopted downstream by the other OpenZFS users (including ZFS on Linux).

cs702 13y ago

I suspect an unmentioned goal of this project is eventually to make the installation of OpenZFS on Linux (and other *ix operating systems) quick and simple, legally running around Oracle's license restrictions.[1] Unsurprisingly, the list of supporting companies[2] does not include Oracle, which surely isn't happy about this project. -- [1] The source code upon which OpenZFS is based was provided by Oracle (Sun) under the CDDL license, which prevents OpenZFS from being distributed in binary form as part of the Linux kernel. [2] http://www.open-zfs.org/wiki/Companies http://www.open-zfs.org/wiki/Companies

synchronise 13y ago
Nothing stopping you from writing a script that automatically compiles and installs the module when you're installing your distro.
- patrickg_zill 13y ago
  I think the Debian install is almost as easy as that - download a .deb package and install it, and it pulls in and installs and compiles everything else.
- ed_blackburn 13y ago
  Homebrew?
- saosebastiao 13y ago
  There are lots of things stopping me from doing that. Like ensuring I don't break everything I touch. Not everybody is a sysadmin.
gonzo 13y ago
You can already install on ZFS in FreeBSD.
- laumars 13y ago
  It's a great pity more ZFS advocates are taking this as an opportunity to get better acquainted with FreeBSD. I've been running FreeBSD on my home server for about a decade now -even before ZFS- and have loved it. But I used to run Linux VMs on top of it. However it's only recently that I've decided to go fully FreeBSD on it, using jails instead of hardware virtualisation. I honestly can't understand why I waited so long to do so. It's proven to be a far more elegant solution for what I needed. While I do still run Linux on my desktop and work with Solaris and linux as my day job; FreeBSD seems a vastly overlooked alternative these days, which I think that's a great pity. its stable, proven and dead to administrate. But each to their own I guess.

oscargrouch 13y ago

you know why this is huge? its the first kernel piece of code that are and can be shared by different open-source operating systems in the kernel codebase! i hope more technologies could get up into this model.. while the democratic open-source ecosystem in userland is a rule this days.. on the kernel land this is not true and that may force us to use a OS instead of other because of some feature that only that Os has, even if we wish to install the other one.. for instance, i love linux, but i also love the BSD´s and want them to grow as much as linux did.. if the good things created in one OS could also be used on other, by a proper port to that kernel, we might not being bullied to accept on OS in favor of another, and be stuck by it! I hope this movement make its way to others kerneland technologies! great news!

simcop2387 13y ago
Not quite the first, but likely to end up one of the most wide spread. The DRM graphics drivers are actually older than ZFS and have been MIT licensed from the beginning (they started from older MIT licensed X11 projects). There's also possibly some other's from the BSD projects (network drivers and such) that are even older than those.
- oscargrouch 13y ago
  yeah, but in those cases you have cited, the interested party get the source and implements it on its own codebase himself eg. microsoft using bsd network layer on windows and freebsd porting linux drm to its own kernel.. this is different.. its aggregated as a product that target several os´s with different implementations for each kernel, but shareing only one core codebase.. this tends to be much more stable and cheap to everybody.. less bug prone, etc.. didnt heard of anything like it..

tete 13y ago

I am curious. What are you using ZFS for?

contingencies 13y ago
https://en.wikipedia.org/wiki/Comparison_of_filesystems#Features https://en.wikipedia.org/wiki/Comparison_of_filesystems#Feat...
- tete 13y ago
  I know. I mostly ask, because a lot of people these days keep nearly every kind of data in databases and ZFS usually isn't the best thing for this (depending on the exact use case of course). It's by far one of the most exciting file systems, for storing "raw" data, but if you are having another layer, your data base system it (again, based on the exact use case) can become an unbearable overhead performancewise.
Sanddancer 13y ago
I'm personally using it on my set of freebsd jailed boxes to provide quota-ing in a useful way, de-duplication of shared files in those quotaed trees, compression of things like the ports tree, etc. Subvolumes are sexy as hell in how you can have one filesystem, but give lots of different attributes to various bits and pieces.

deleted 13y ago

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fsckin 13y ago

I built a 16TB raidz home office server this weekend using Ubuntu and ZFS on Linux[0]. It worked great out of the box. I was even able to import a pool created on another server without any problem. Of course, your mileage may vary. I was using FreeNAS previously (mainly for the ZFS support to keep my data safe and not spend a bunch on raid controllers) and kept getting bogged down by feeling the need to grok jails. I think jails are terrific in theory, but a pain to work with if you're not intimately familiar with them. Maybe it's just the way it works on FreeNAS, but newly created jails (by default on FreeNAS) were getting a new virtual IP addresses, which really threw me for a loop. Add to that frustration trying to get all the permissions correct just to make a few different services work together started to get really painful. The drop-dead simplicity of setting up exactly what I had previously on a fresh Ubuntu box with native ZFS port really warmed my cockles. [0] http://zfsonlinux.org/ http://zfsonlinux.org/

mikevm 13y ago
What's the advantage of using ZFS RAIDZ over mdadm? I thought that mdadm was more flexible in growing your RAID array.
- KaiserPro 13y ago
  The documentation for raidZ is wonderful, and the commands are logical. mdam is a pain, and doesn't provide block level checksums, so you can easily get silent corruption.
- cdjk 13y ago
  I think the primary advantage is that ZFS collapses all the standard filesystem abstractions. With mdadm or hardware raid you have a raid controller (which could be mdadm), volume manager (i.e. lvm), and filesystem (ext4, xfs, etc). ZFS combines all of that into one. It's really a different philosophy, but means that things like creating a new filesystem is almost instant (and CoW, snapshots, replication are all easy - although perhaps that's possible with the traditional abstractions as well).
- craigyk 13y ago
  I think the RAIDZ is also less susceptible to data loss due to the RAID layer and the filesystem being tightly integrated.

deleted 13y ago

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acd 13y ago

ZFS is the best thing that happened in storage! Big thanks to the developers! Happily uses Western Digital 25AV 2.5 disks. Will probably use WD Red series. Total remote backup time with ZFS incremental snapshots negligible.

magg 13y ago

the site is lacking the Mac OS X version called Zevo: http://getgreenbytes.com/solutions/zevo/ http://getgreenbytes.com/solutions/zevo/. It was developed by Don Brady, formerly a Senior Software Engineer at Apple

adsr 13y ago
And it's at Zpool 28 already.

cmccabe 13y ago

I have a lot of respect for those working on this project, but realistically, if you use Linux, using an out-of-tree filesystem is just asking for pain-- lots of it. I would never use this on a production system. You know how painful out-of-tree video drivers are? Yeah. Imagine that, only now with the potential for data loss and divergent on-disk formats. And if it's your root fs, you can forget about booting if there's a problem. Sure ZFS has a great reputation, but a lot of that came from how well-integrated it was into Solaris and how much QA was done on it. Neither of those things were ever true (or are going to be true in the future) for the various ZFS-on-Linux projects (yes, there are multiple.) The comments about btrfs are about 5 years out of date. SuSE has already shipped btrfs in their "stable" 11.1 distribution, and Red Hat is going to do so in RHEL7. Give it a chance.

cbsmith 13y ago
> The comments about btrfs are about 5 years out of date. Not really. I've tried it, and it still has pain points I'd not like to have in my filesystem. It's like ZFS almost a decade ago (and I'm not talking about features)... although ZFS on Linux vs. btrfs on Linux... right now I'd still go with btrfs. > Neither of those things were ever true (or are going to be true in the future) for the various ZFS-on-Linux projects (yes, there are multiple.) I believe there is a shift with regard to this, as demonstrated by the Gentoo project's integration of ZFS.
- unhammer 13y ago
  > Not really. I've tried it, and it still has pain points I'd not like to have in my filesystem. It's like ZFS almost a decade ago (and I'm not talking about features)... although ZFS on Linux vs. btrfs on Linux... right now I'd still go with btrfs. Care to elaborate? I've never tried ZFS, but been very happy with btrfs for my smalltime personal usage, I'm wondering why people find it so painful in comparison.
  - cbsmith 13y ago
    Well, there's just the general lack luster performance: http://www.phoronix.com/scan.php?page=article&item=linux_311_filesystems&num=3 http://www.phoronix.com/scan.php?page=article&item=linux_311... I've also seen particularly bad pain points when doing things like using it with an NFS server.

contingencies 13y ago

I dabbled in ZFS on FreeBSD + OpenSolaris 3 years back. It was nice and all, but it hasn't been worth the overhead of running another OS to get its features since. I'm therefore glad to see some unity in the ZFS community to create more trust around its use in Linux, and proud to see my beloved Gentoo in the list of standard-bearers! Bring on the unrivalled pragmatism. Quack quack. Observation: Gentoo packages still point to http://zfsonlinux.org/ http://zfsonlinux.org/ not to http://open-zfs.org/ http://open-zfs.org/ .. is this the same code? I suppose so. Further observation: The kernel code looks like, as packaged by Gentoo, it can only be compiled as a module. Generally I disable LKMs on production systems. Grumble.

dmpk2k 13y ago
it hasn't been worth the overhead of running another OS to get its features since. That's a rather cavalier attitude towards the integrity of your data. :/ I can replace operating systems. It's a lot more difficult to replace lost or silently-corrupted data. That makes data integrity one of my prime concerns, which it should be for any production systems.
- contingencies 13y ago
  That's a rather cavalier attitude towards the integrity of your data ... data integrity one of my prime concerns, which it should be for any production systems. Different projects have different resources and requirements. There's far more ways than just ZFS to provide for data redundancy and integrity (TMTOWTDI). (Edit: why the downvote? Geez.)
  - dmpk2k 13y ago
    Downvote wasn't me. I agree with the sentiment regarding requirements. However, I disagree with the bit regarding data redundancy and integrity. You can do it other ways, but that doesn't make it a good idea; it's a bit like Greenspun's Tenth Rule, but for data. ZFS, or something like it (and there isn't anything else like it), is the foundation of any modern setup where data is important. Because it's not on Linux is a terrible reason. If your data is important, then you'll need to look elsewhere than Linux for the servers where the data sleeps. The importance of data requires it. If data is relatively unimportant, then you're right. There are few domains where that's true nowadays though.

phryk 13y ago

FORK YEAH, this is what I've been waiting for the last 2 or so years. <3