8 ms·

FreeBSD and ZFS

136 points by liuw 11y ago

lomnakkus 11y ago
Yes, happily the ZFS license (CDDL) and (star)BSD licenses seem to be compatible. Yay for the BSDs of the world! Unfortunately, most of the OSS/Free Software world is running a Linux kernel whose license (GPLv2) isn't compatible with the CDDL according to current thinking by most of the people who know about these things. End of story, AFAICT. (I mean there's a theoretical possibility of relicensing the Linux kernel, but given the contributor profile it's probably impossible in any practical sense. AFAICT it would be far more likely/practical for ZFS to be re-licensed under a GPL-compatible license if only the corporate overlords were so inclined.) EDIT: Just a minor edit: I didn't mean that it's "unfortunate" that most of the OSS/Free Software world is running Linux. It works pretty damn well. My "unfortunately" remark was merely about the fact that licenses may be (or are) incompatible.
- noinsight 11y ago
  > it would be far more likely/practical for ZFS to be re-licensed under a GPL-compatible license if only the corporate overlords were so inclined. I feel like that ship has sailed since there's Btrfs for Linux too - which also originated at Oracle. I've always been curious why they kept working on Btrfs after acquiring Sun since they could've just relicensed ZFS to GPL/whatever. Then again, I've also always been curious why people still keep glamoring over ZFS for Linux when Btrfs exists now, which, as far as I understand, is comparable to ZFS and a fresh implementation (for what that's worth).
  - the_ancient 11y ago
    Because ZFS is 100000000000X better than btrfs... the ZFS commands are more logical, and better designed The ZFS FileSystem is truely enterprise ready... btrfs is atleast 5 years away from being production ready btrfs has all kinds of bugs and issues. zfs did not hold to legacy conventions, they looked at filesystems in a differnet way. btrfs attempts to hold on the traditional filesystem methodology and shoehorn more modern ideas in to that traditional framework, and IMO it does not work at all the zfs and zpool commands are brilliant, intuitive, and easy to use. The btrfs command structure is complicated, non-intuitive, and antiquated
  - gherkin0 11y ago
    > Then again, I've also always been curious why people still keep glamoring over ZFS for Linux when Btrfs exists now, which, as far as I understand, is comparable to ZFS and a fresh implementation (for what that's worth). My understanding is that Btrfs is still considered less stable than ZFS, or at least has been fairly recently.
  - lomnakkus 11y ago
    > I feel like that ship has sailed since there's Btrfs for Linux too - which also originated at Oracle. Unfortunately, I think you may be right. It's just sad -- because probably nobody who's anyone at Oracle cares and/or understands. > Then again, I've also always been curious why people still keep glamoring over ZFS for Linux when Btrfs exists now, which, as far as I understand, is comparable to ZFS and a fresh implementation (for what that's worth). It is mostly comparable feature-wise, it's just that it hasn't achieved anywhere near the same level of stability for anything other than single-device usage. (At least that's my understanding from following the mailing list for years and years.)
  - usefulcat 11y ago
    Bear in mind that many of those who are interested in ZFS are interested in it specifically because they care a lot about not losing data. With that in mind, let's see what the btrfs wiki has to say about the stability of btrfs: "Is btrfs stable? Short answer: Maybe." https://btrfs.wiki.kernel.org/index.php/FAQ#Is_btrfs_stable.3F https://btrfs.wiki.kernel.org/index.php/FAQ#Is_btrfs_stable.... Maybe it's just me, but I'm more than a little concerned by the fact that btrfs has been in development for over 8 years and still doesn't seem to be considered safe to use for storing anything I really care about.
  - Sanddancer 11y ago
    ZFS has a considerable number of very useful features that Btrfs doesn't have. For example, under ZFS, you can delegate administration of a filesystem (subvolume in Btrfs terms) to a normal user. In doing so, you can, for example, set up each user's home directory as its own subvolume, allowing for per-account snapshots, and their own sets of subvolumes which can have differing properties as-needed. ZFS also has support in-driver for sharing volumes, which means nfs shares, and smb shares (unfortunately not under FreeBSD yet) work natively with the filesystem, and can be exported there, instead of needing to muck around with config files and then kicking things in the proper order. Btrfs is still Not There Yet for a lot of the advantages ZFS has over traditional filesystems. It has a some, and some are half-baked, like its offline deduplication, but is still missing a considerable number. Maybe in five years Btrfs will catch up, but it's not here now. Rearding licensing, the Linux kernel devs could also relicense to allow for cddl co-existence. Unfortunately, the petulance from such groups as the SFLC makes that very unlikely.
  - michaelmrose 11y ago
    It is comparable in that they are both filesystems... Supposedly the situation has been improving but at least as of months ago compared to zfs performance was horrible, features were lacking, and likelihood of data loss was a lot higher.
- bch 11y ago
  > Unfortunately, most of the OSS/Free Software world is running a Linux kernel whose license (GPLv2) isn't compatible with the CDDL according to current thinking by most of the people who know about these things. This[0] is one of the more interesting reviews of this I've seen in a long time, including what seems like a footnote about dtrace at the end that I thought was a shocker. [0] https://softwarefreedom.org/resources/2016/linux-kernel-cddl.html https://softwarefreedom.org/resources/2016/linux-kernel-cddl...
  - hackcasual 11y ago
    Yeah, anyone saying this is a cut and dry matter doesn't really have a true appreciation for how murky legal waters can get.
  - shiftoutbox 11y ago
    Why must it be relicensed . Why not let it just be . Can the Linux people stop trying to tell everyone that everything needs to be gpl'ed or gpl compatible. It's like a 3 year old wining about how they can't get a second cookie .
    - lomnakkus 11y ago
      I don't think you appreciate the complexities of copyright law as codified in the Berne convention, etc. (I hate it too, but that's no excuse to just ignore it.) EDIT: Sorry, I accidentally downvoted you. Apologies.
      - shiftoutbox 11y ago
        I work with a guy who has cddl'd his project . He likes the license ; I don't nag him to change it to an isc license . He has his reasons for the cddl, I might not agree with all of it but I am great full he open sourced it . If sun /oracle didn't open source zfs or dtrace we would be all be using Solaris and paying to use it . So if FreeBSD , NetBSD , illumos have a properly compatable licenses for zfs . Embrace that ; if you don't want to, check out dragonflybsd and hammerfs, look at btree on Linux , check out openbfs on haiku . I can't stress this enough Canonical is a shitty company who needs to make waves to stay relevant . I don't know why anyone uses their crap . Wait I remember they are a commercial company with a marketing department who gets paid to polish that turd . What was so bad about Debian ? If you don't like Debian Why not give a a bsd a try . Hell why not just try Smart os and a lx-branded zone . You get zfs , dtrace , and all of the ful of full Linux comparability .
- corv 11y ago
  Or one could simply use FreeBSD because even if ZFS was relicensed the integration of ZFS throughout the Linux ecosystem is nowhere near FreeBSD's.
  - protomyth 11y ago
    PC-BSD has made a real effort to make that integration user facing in a nice UI.
- trollian 11y ago
  But freebsd with zfs isn't BSD licensed. In many ways it's under a much more restrictive license than Linux.
Sir_Cmpwn 11y ago
This seems like an awfully masturbatory piece riding the recently renewed wave of grumpiness about the ZFS/Linux/GPL nonsense. I'm not impressed. Everyone already knows ZFS and BSD are in bed together.
web007 11y ago
This feels very self-serving. There's no need for BSD to comment on their "longstanding relationship" with ZFS if they're only saying "we have it and it works within our framework" versus adding something constructive to the dialog on its licensing in Linux. It's awesome that the BSD and ZFS licenses are compatible and that it works well. It just has nothing to do with the headlines they are addressing.
- rbanffy 11y ago
  It is yet another way of them saying "See? Our license is better than theirs."
- ksec 11y ago
  Like there is no need to market its product then?
- Sanddancer 11y ago
  No, the FreeBSD foundation is showing that different entities, with different licenses, can cooperate. As the SFLC mentioned in their original posting, combining ZFS in the kernel feels little more than damnum absque injuria. In order for any judgement to be laid, there has to be shown some sort of injured party. Who is injured exactly by integrating a kernel module with primarily CDDL code with the Linux kernel, which itself already includes many binary only files where the licensing is questionable?
  - pilif 11y ago
    > Who is injured exactly by integrating a kernel module with primarily CDDL code with the Linux kernel Oracle as the sole copyright holder of zfs might be because thy lose potential Solaris sales when zfs is distributed with Linux this way. At least they could argue that before some court
    - cyphar 11y ago
      Oracle was the original copyright holder before the OpenSolaris fiasco and Illumos was forked.
ksec 11y ago
Offtopic, the next post on the blog is about FreeBSD and RISC-V, what i find interesting is they are both from UC Berkeley.
random_upvoter 11y ago
A while back I was considering Freenas and in the documentation/forums I read dire warnings about running ZFS with less than 8 gigabyte of ram. Apparently, this could actually put your data at risk. I was a bit nonplussed by this. The least I would expect from a file system is that it degrades gracefully. I wonder if anyone knows more about this?
- oakwhiz 11y ago
  I've been running ZFS on a machine with 768 MB of RAM and there have been no issues. If you set the size of the ARC cache according to your needs and you do not use deduplication then you won't encounter any issues. Deduplication requires a giant hash table and is rarely beneficial.
- mkup 11y ago
  I run FreeBSD with ZFS on the home server, which primary purpose is storing and processing video files from two surveillance cameras. ZFS pool is created as RAID-1 array of two 2TB HDDs. Server has 2GB DDR2 RAM, but ZFS in-memory cache is restricted to 512MB. OS architecture is x64. ZFS deduplication is turned off. CPU is Intel Atom D510. Not very fast, but it was chosen for low power consumption considering special case when grid power goes off and whole system (including server, cameras and PoE switch) runs from backup DC batteries. I've never had any problems with this setup during 3+ years. It's rock solid and even has extra CPU time to run motion detection software and Transmission (BitTorrent client).
- anexprogrammer 11y ago
  FreeNAS do seem to recommend ludicrous minimum amounts of RAM, even without dedupe. If you ferret around their forums there seems to have been some history of data loss on low RAM machines. I don't know if it's something they've introduced but I've not seen mention of similar issues around the FreeBSD forums. If you compare with the FreeBSD guide to tuning ZFS, they recommend 1GB and up and give settings for tuning for 768 MB. They mention that in practice dedupe would like upto 5GB / TB, so I've never bothered. 99 out of 100 don't need dedupe anyway - compression will be better. I've never had an issue running FreeBSD + ZFS on a 1GB machine, which was my file server for several years. I ran FreeNAS with 1GB for around a year without issue. I'm now running a HP microserver with 16GB which gives 12GB to ARC.
cm3 11y ago
FWIW HammerFS dedup doesn't require much RAM.

136 points by liuw 11y ago

Yes, happily the ZFS license (CDDL) and (star)BSD licenses seem to be compatible. Yay for the BSDs of the world! Unfortunately, most of the OSS/Free Software world is running a Linux kernel whose license (GPLv2) isn't compatible with the CDDL according to current thinking by most of the people who know about these things. End of story, AFAICT. (I mean there's a theoretical possibility of relicensing the Linux kernel, but given the contributor profile it's probably impossible in any practical sense. AFAICT it would be far more likely/practical for ZFS to be re-licensed under a GPL-compatible license if only the corporate overlords were so inclined.) EDIT: Just a minor edit: I didn't mean that it's "unfortunate" that most of the OSS/Free Software world is running Linux. It works pretty damn well. My "unfortunately" remark was merely about the fact that licenses may be (or are) incompatible.

noinsight 11y ago
> it would be far more likely/practical for ZFS to be re-licensed under a GPL-compatible license if only the corporate overlords were so inclined. I feel like that ship has sailed since there's Btrfs for Linux too - which also originated at Oracle. I've always been curious why they kept working on Btrfs after acquiring Sun since they could've just relicensed ZFS to GPL/whatever. Then again, I've also always been curious why people still keep glamoring over ZFS for Linux when Btrfs exists now, which, as far as I understand, is comparable to ZFS and a fresh implementation (for what that's worth).
- the_ancient 11y ago
  Because ZFS is 100000000000X better than btrfs... the ZFS commands are more logical, and better designed The ZFS FileSystem is truely enterprise ready... btrfs is atleast 5 years away from being production ready btrfs has all kinds of bugs and issues. zfs did not hold to legacy conventions, they looked at filesystems in a differnet way. btrfs attempts to hold on the traditional filesystem methodology and shoehorn more modern ideas in to that traditional framework, and IMO it does not work at all the zfs and zpool commands are brilliant, intuitive, and easy to use. The btrfs command structure is complicated, non-intuitive, and antiquated
- gherkin0 11y ago
  > Then again, I've also always been curious why people still keep glamoring over ZFS for Linux when Btrfs exists now, which, as far as I understand, is comparable to ZFS and a fresh implementation (for what that's worth). My understanding is that Btrfs is still considered less stable than ZFS, or at least has been fairly recently.
- lomnakkus 11y ago
  > I feel like that ship has sailed since there's Btrfs for Linux too - which also originated at Oracle. Unfortunately, I think you may be right. It's just sad -- because probably nobody who's anyone at Oracle cares and/or understands. > Then again, I've also always been curious why people still keep glamoring over ZFS for Linux when Btrfs exists now, which, as far as I understand, is comparable to ZFS and a fresh implementation (for what that's worth). It is mostly comparable feature-wise, it's just that it hasn't achieved anywhere near the same level of stability for anything other than single-device usage. (At least that's my understanding from following the mailing list for years and years.)
- usefulcat 11y ago
  Bear in mind that many of those who are interested in ZFS are interested in it specifically because they care a lot about not losing data. With that in mind, let's see what the btrfs wiki has to say about the stability of btrfs: "Is btrfs stable? Short answer: Maybe." https://btrfs.wiki.kernel.org/index.php/FAQ#Is_btrfs_stable.3F https://btrfs.wiki.kernel.org/index.php/FAQ#Is_btrfs_stable.... Maybe it's just me, but I'm more than a little concerned by the fact that btrfs has been in development for over 8 years and still doesn't seem to be considered safe to use for storing anything I really care about.
- Sanddancer 11y ago
  ZFS has a considerable number of very useful features that Btrfs doesn't have. For example, under ZFS, you can delegate administration of a filesystem (subvolume in Btrfs terms) to a normal user. In doing so, you can, for example, set up each user's home directory as its own subvolume, allowing for per-account snapshots, and their own sets of subvolumes which can have differing properties as-needed. ZFS also has support in-driver for sharing volumes, which means nfs shares, and smb shares (unfortunately not under FreeBSD yet) work natively with the filesystem, and can be exported there, instead of needing to muck around with config files and then kicking things in the proper order. Btrfs is still Not There Yet for a lot of the advantages ZFS has over traditional filesystems. It has a some, and some are half-baked, like its offline deduplication, but is still missing a considerable number. Maybe in five years Btrfs will catch up, but it's not here now. Rearding licensing, the Linux kernel devs could also relicense to allow for cddl co-existence. Unfortunately, the petulance from such groups as the SFLC makes that very unlikely.
- michaelmrose 11y ago
  It is comparable in that they are both filesystems... Supposedly the situation has been improving but at least as of months ago compared to zfs performance was horrible, features were lacking, and likelihood of data loss was a lot higher.
bch 11y ago
> Unfortunately, most of the OSS/Free Software world is running a Linux kernel whose license (GPLv2) isn't compatible with the CDDL according to current thinking by most of the people who know about these things. This[0] is one of the more interesting reviews of this I've seen in a long time, including what seems like a footnote about dtrace at the end that I thought was a shocker. [0] https://softwarefreedom.org/resources/2016/linux-kernel-cddl.html https://softwarefreedom.org/resources/2016/linux-kernel-cddl...
- hackcasual 11y ago
  Yeah, anyone saying this is a cut and dry matter doesn't really have a true appreciation for how murky legal waters can get.
- shiftoutbox 11y ago
  Why must it be relicensed . Why not let it just be . Can the Linux people stop trying to tell everyone that everything needs to be gpl'ed or gpl compatible. It's like a 3 year old wining about how they can't get a second cookie .
  - lomnakkus 11y ago
    I don't think you appreciate the complexities of copyright law as codified in the Berne convention, etc. (I hate it too, but that's no excuse to just ignore it.) EDIT: Sorry, I accidentally downvoted you. Apologies.
    - shiftoutbox 11y ago
      I work with a guy who has cddl'd his project . He likes the license ; I don't nag him to change it to an isc license . He has his reasons for the cddl, I might not agree with all of it but I am great full he open sourced it . If sun /oracle didn't open source zfs or dtrace we would be all be using Solaris and paying to use it . So if FreeBSD , NetBSD , illumos have a properly compatable licenses for zfs . Embrace that ; if you don't want to, check out dragonflybsd and hammerfs, look at btree on Linux , check out openbfs on haiku . I can't stress this enough Canonical is a shitty company who needs to make waves to stay relevant . I don't know why anyone uses their crap . Wait I remember they are a commercial company with a marketing department who gets paid to polish that turd . What was so bad about Debian ? If you don't like Debian Why not give a a bsd a try . Hell why not just try Smart os and a lx-branded zone . You get zfs , dtrace , and all of the ful of full Linux comparability .
corv 11y ago
Or one could simply use FreeBSD because even if ZFS was relicensed the integration of ZFS throughout the Linux ecosystem is nowhere near FreeBSD's.
- protomyth 11y ago
  PC-BSD has made a real effort to make that integration user facing in a nice UI.
trollian 11y ago
But freebsd with zfs isn't BSD licensed. In many ways it's under a much more restrictive license than Linux.

Sir_Cmpwn 11y ago

This seems like an awfully masturbatory piece riding the recently renewed wave of grumpiness about the ZFS/Linux/GPL nonsense. I'm not impressed. Everyone already knows ZFS and BSD are in bed together.

web007 11y ago

This feels very self-serving. There's no need for BSD to comment on their "longstanding relationship" with ZFS if they're only saying "we have it and it works within our framework" versus adding something constructive to the dialog on its licensing in Linux. It's awesome that the BSD and ZFS licenses are compatible and that it works well. It just has nothing to do with the headlines they are addressing.

rbanffy 11y ago
It is yet another way of them saying "See? Our license is better than theirs."
ksec 11y ago
Like there is no need to market its product then?
Sanddancer 11y ago
No, the FreeBSD foundation is showing that different entities, with different licenses, can cooperate. As the SFLC mentioned in their original posting, combining ZFS in the kernel feels little more than damnum absque injuria. In order for any judgement to be laid, there has to be shown some sort of injured party. Who is injured exactly by integrating a kernel module with primarily CDDL code with the Linux kernel, which itself already includes many binary only files where the licensing is questionable?
- pilif 11y ago
  > Who is injured exactly by integrating a kernel module with primarily CDDL code with the Linux kernel Oracle as the sole copyright holder of zfs might be because thy lose potential Solaris sales when zfs is distributed with Linux this way. At least they could argue that before some court
  - cyphar 11y ago
    Oracle was the original copyright holder before the OpenSolaris fiasco and Illumos was forked.

ksec 11y ago

Offtopic, the next post on the blog is about FreeBSD and RISC-V, what i find interesting is they are both from UC Berkeley.

random_upvoter 11y ago

A while back I was considering Freenas and in the documentation/forums I read dire warnings about running ZFS with less than 8 gigabyte of ram. Apparently, this could actually put your data at risk. I was a bit nonplussed by this. The least I would expect from a file system is that it degrades gracefully. I wonder if anyone knows more about this?

oakwhiz 11y ago
I've been running ZFS on a machine with 768 MB of RAM and there have been no issues. If you set the size of the ARC cache according to your needs and you do not use deduplication then you won't encounter any issues. Deduplication requires a giant hash table and is rarely beneficial.
mkup 11y ago
I run FreeBSD with ZFS on the home server, which primary purpose is storing and processing video files from two surveillance cameras. ZFS pool is created as RAID-1 array of two 2TB HDDs. Server has 2GB DDR2 RAM, but ZFS in-memory cache is restricted to 512MB. OS architecture is x64. ZFS deduplication is turned off. CPU is Intel Atom D510. Not very fast, but it was chosen for low power consumption considering special case when grid power goes off and whole system (including server, cameras and PoE switch) runs from backup DC batteries. I've never had any problems with this setup during 3+ years. It's rock solid and even has extra CPU time to run motion detection software and Transmission (BitTorrent client).
anexprogrammer 11y ago
FreeNAS do seem to recommend ludicrous minimum amounts of RAM, even without dedupe. If you ferret around their forums there seems to have been some history of data loss on low RAM machines. I don't know if it's something they've introduced but I've not seen mention of similar issues around the FreeBSD forums. If you compare with the FreeBSD guide to tuning ZFS, they recommend 1GB and up and give settings for tuning for 768 MB. They mention that in practice dedupe would like upto 5GB / TB, so I've never bothered. 99 out of 100 don't need dedupe anyway - compression will be better. I've never had an issue running FreeBSD + ZFS on a 1GB machine, which was my file server for several years. I ran FreeNAS with 1GB for around a year without issue. I'm now running a HP microserver with 16GB which gives 12GB to ARC.

cm3 11y ago

FWIW HammerFS dedup doesn't require much RAM.