6 ms·

Things you can't do with ZFS: - Use it together with GPL-licensed software

by markild 11y ago

moviuro 11y ago
You can. ZOL does that. Blame the GPL plague-like principle.
- baq 11y ago
  blame Sun and Oracle for releasing it under a license designed to be incompatible with GPL.
  - bestham 11y ago
    According to Bryan Cantrill that is not at all accurate https://youtu.be/-zRN7XLCRhc?t=1364 https://youtu.be/-zRN7XLCRhc?t=1364 * Edited for wrong link
    - baldfat 11y ago
      Listen to it and the whole point he is making is we had to make way for proprietary drivers and not to block it being compatible with GPL. Seem very much a grammar Judo to say we didn't go out of the way to be anti-compatible with GPL but we invented a copy left license so we could never be compatible with GPL.
      - bestham 11y ago
        Well how much work can you expect a for-profit-company to do in order to release their software as open source? They choose a licence that worked for them, then and there because of reasons. This included the work on ZFS. There are operating systems that have licences that permit the ZFS code in the kernel. What reasons did SUN have to specifically block the Linux kernel but not BSD / Darwin ? The choice of license has everything to do whit what license SUN was comfortable using and nothing to do with keeping GNU/Linux out of the party. If the answer is that a lot of their competitors at the time were invested in GNU/Linux and thus could not use their code, that is a very short sighted move.
        baldfat 11y ago
        > Well how much work can you expect a for-profit-company to do in order to release their software as open source? A lot actually I expect them to make open source software and in all regards this has happened. http://www.infoworld.com/article/2914643/open-source-software/rise-and-rise-of-open-source.html http://www.infoworld.com/article/2914643/open-source-softwar...
    - Fedjmike 11y ago
      Couldn't they have dual licensed it under both the CDDL and GPL? CDDL for when they distribute it with the closed drivers, then additionally distribute the source under the GPL allowing it to be used in Linux.
      - protomyth 11y ago
        Probably not, since that would have allowed someone to add GPL-only code to it which couldn't be distributed with the whole. The video is very good and you can follow-up with https://www.youtube.com/watch?v=l6XQUciI-Sc https://www.youtube.com/watch?v=l6XQUciI-Sc
        yrro 11y ago
        I don't understand; Sun would not have been obligated to accept contributions that were not similarly dual-licensed...
        protomyth 11y ago
        The same theory as the GPL, why allow people to use your work if you cannot use their additions in return?
- csirac2 11y ago
  Both are to blame. Neither are to blame. Much of the success of Linux has been attributed to the GPL. It certainly had a role to play in opening up WRT firmware. The truth is that the GPL is a pretty restrictive license. I don't think it's fair to blame anyone for the fact that it's not compatible with much. That's its defining feature and the main reason people choose it; so if it blocks ZoL, it's working as intended. Which I consider a great loss. ZFS is fantastic. I use the BSD 2-clause license on my own stuff, but I can think of situations where I'd rather use GPL.
  - baldfat 11y ago
    There seems to be a ton of commercial and proprietary software and services on Linux with the GPL. Too many people just don't understand the GPL. If you make changes you must share the changes does not equal Plague Like. GPL is the most used and misunderstood license. It is more complicated now than I wish it was but it has given birth to so much. I prefer it to BSD or MIT due to the share a like nature of GPL. http://www.gnu.org/licenses/gpl-faq.en.html http://www.gnu.org/licenses/gpl-faq.en.html
    - dspillett 11y ago
      > If you make changes you must share the changes does not equal Plague Like. You don't even have to share the changes with the unwashed masses, or even the original author, just the people you sell/give the resulting program/service too. Of course they are free to distribute the changes more freely, the license explicitly states it is a breach for you to try block that, but you don't have to.
      - baldfat 11y ago
        The GPL does not require you to release your modified version, or any part of it. You are free to make modifications and use them privately, without ever releasing them. This applies to organizations (including companies), too; an organization can make a modified version and use it internally without ever releasing it outside the organization. But if you release the modified version to the public in some way, the GPL requires you to make the modified source code available to the program's users, under the GPL. Thus, the GPL gives permission to release the modified program in certain ways, and not in other ways; but the decision of whether to release it is up to you.
madez 11y ago
You can use both together all day long even in your business. You must only not distribute both together.
- SirMaster 11y ago
  Sure you can, Proxmox has distributed ZFS with it's custom Debian-based OS for over a year now. ZFS comes pre-installed and the installer for Proxmox even gives you the options to install the OS directly onto a bootable zpool that is created automatically by the installer itself.
throwaway7767 11y ago
The thing I miss most in ZFS (aside from a native in-kernel linux port, as I've found ZoL to be kinda buggy) is to be able to grow zdevs. I can add a new zdev, I can remove them, but I can't add one disk to my 7-disk RAIDZ2. MD RAID has no problem with this. Also, if you add zdevs later, you will never get full performance again as the striping will be off (putting more writes on the zdevs with more free space), and there's no 'rebalance' kind of thing (I've seen some scripts that just move stuff around, but I've never seen any evidence that they work, and I really doubt that they do based on my understanding of zdev allocation).
- nathan7 11y ago
  I'm assuming you mean vdevs — you can resize zvols (virtual block devices) just fine. (and you can even grow disk-type vdevs, though they'll be somewhat unbalanced)
  - throwaway7767 11y ago
    Yeah, sorry, edited. It's mainly the ability to resize RAIDZ or RAIDZ2 zdevs that would be really helpful.
- Scramblejams 11y ago
  Me too. I've added so many drives in onesies and twosies to so many MD RAID5/6 arrays over the years that I simply can't confidently deploy ZFS for that case.
- cmurf 11y ago
  md RAID will require a lengthy reshape. BTRFS supports adding a new drive, reshape (balance) is optional.
  - throwaway7767 11y ago
    > md RAID will require a lengthy reshape Array reshapes are rare, and it'll only use idle IO bandwidth anyway. Redundancy is guaranteed during the whole process. So I don't see this as a problem. > BTRFS supports adding a new drive, reshape (balance) is optional Thanks for pointing this out. I didn't know btrfs supported array reshapes. I'm waiting for it to mature (RAID5/6 was only added in 3.19, for example) but I expect I'll switch over at some point, probably at the point it's considered "boring" (exactly the experience I want from my filesystems).
oskarth 11y ago
Your comment would be more honest if it started with "Things you can't do with GPL".
- deleted 11y ago
  [deleted]
switch007 11y ago
- Use deduplication in a production environment [1] [1] http://serverfault.com/questions/234475/zfs-destroying-deduplicated-zvol-or-data-set-stalls-the-server-how-to-recover http://serverfault.com/questions/234475/zfs-destroying-dedup...

Things you can't do with ZFS: - Use it together with GPL-licensed software

by markild 11y ago

Things you can't do with ZFS: - Use it together with GPL-licensed software

moviuro 11y ago

You can. ZOL does that. Blame the GPL plague-like principle.

baq 11y ago
blame Sun and Oracle for releasing it under a license designed to be incompatible with GPL.
- bestham 11y ago
  According to Bryan Cantrill that is not at all accurate https://youtu.be/-zRN7XLCRhc?t=1364 https://youtu.be/-zRN7XLCRhc?t=1364 * Edited for wrong link
  - baldfat 11y ago
    Listen to it and the whole point he is making is we had to make way for proprietary drivers and not to block it being compatible with GPL. Seem very much a grammar Judo to say we didn't go out of the way to be anti-compatible with GPL but we invented a copy left license so we could never be compatible with GPL.
    - bestham 11y ago
      Well how much work can you expect a for-profit-company to do in order to release their software as open source? They choose a licence that worked for them, then and there because of reasons. This included the work on ZFS. There are operating systems that have licences that permit the ZFS code in the kernel. What reasons did SUN have to specifically block the Linux kernel but not BSD / Darwin ? The choice of license has everything to do whit what license SUN was comfortable using and nothing to do with keeping GNU/Linux out of the party. If the answer is that a lot of their competitors at the time were invested in GNU/Linux and thus could not use their code, that is a very short sighted move.
      - baldfat 11y ago
        > Well how much work can you expect a for-profit-company to do in order to release their software as open source? A lot actually I expect them to make open source software and in all regards this has happened. http://www.infoworld.com/article/2914643/open-source-software/rise-and-rise-of-open-source.html http://www.infoworld.com/article/2914643/open-source-softwar...
  - Fedjmike 11y ago
    Couldn't they have dual licensed it under both the CDDL and GPL? CDDL for when they distribute it with the closed drivers, then additionally distribute the source under the GPL allowing it to be used in Linux.
    - protomyth 11y ago
      Probably not, since that would have allowed someone to add GPL-only code to it which couldn't be distributed with the whole. The video is very good and you can follow-up with https://www.youtube.com/watch?v=l6XQUciI-Sc https://www.youtube.com/watch?v=l6XQUciI-Sc
      - yrro 11y ago
        I don't understand; Sun would not have been obligated to accept contributions that were not similarly dual-licensed...
        protomyth 11y ago
        The same theory as the GPL, why allow people to use your work if you cannot use their additions in return?
csirac2 11y ago
Both are to blame. Neither are to blame. Much of the success of Linux has been attributed to the GPL. It certainly had a role to play in opening up WRT firmware. The truth is that the GPL is a pretty restrictive license. I don't think it's fair to blame anyone for the fact that it's not compatible with much. That's its defining feature and the main reason people choose it; so if it blocks ZoL, it's working as intended. Which I consider a great loss. ZFS is fantastic. I use the BSD 2-clause license on my own stuff, but I can think of situations where I'd rather use GPL.
- baldfat 11y ago
  There seems to be a ton of commercial and proprietary software and services on Linux with the GPL. Too many people just don't understand the GPL. If you make changes you must share the changes does not equal Plague Like. GPL is the most used and misunderstood license. It is more complicated now than I wish it was but it has given birth to so much. I prefer it to BSD or MIT due to the share a like nature of GPL. http://www.gnu.org/licenses/gpl-faq.en.html http://www.gnu.org/licenses/gpl-faq.en.html
  - dspillett 11y ago
    > If you make changes you must share the changes does not equal Plague Like. You don't even have to share the changes with the unwashed masses, or even the original author, just the people you sell/give the resulting program/service too. Of course they are free to distribute the changes more freely, the license explicitly states it is a breach for you to try block that, but you don't have to.
    - baldfat 11y ago
      The GPL does not require you to release your modified version, or any part of it. You are free to make modifications and use them privately, without ever releasing them. This applies to organizations (including companies), too; an organization can make a modified version and use it internally without ever releasing it outside the organization. But if you release the modified version to the public in some way, the GPL requires you to make the modified source code available to the program's users, under the GPL. Thus, the GPL gives permission to release the modified program in certain ways, and not in other ways; but the decision of whether to release it is up to you.

madez 11y ago

You can use both together all day long even in your business. You must only not distribute both together.

SirMaster 11y ago
Sure you can, Proxmox has distributed ZFS with it's custom Debian-based OS for over a year now. ZFS comes pre-installed and the installer for Proxmox even gives you the options to install the OS directly onto a bootable zpool that is created automatically by the installer itself.

throwaway7767 11y ago

The thing I miss most in ZFS (aside from a native in-kernel linux port, as I've found ZoL to be kinda buggy) is to be able to grow zdevs. I can add a new zdev, I can remove them, but I can't add one disk to my 7-disk RAIDZ2. MD RAID has no problem with this. Also, if you add zdevs later, you will never get full performance again as the striping will be off (putting more writes on the zdevs with more free space), and there's no 'rebalance' kind of thing (I've seen some scripts that just move stuff around, but I've never seen any evidence that they work, and I really doubt that they do based on my understanding of zdev allocation).

nathan7 11y ago
I'm assuming you mean vdevs — you can resize zvols (virtual block devices) just fine. (and you can even grow disk-type vdevs, though they'll be somewhat unbalanced)
- throwaway7767 11y ago
  Yeah, sorry, edited. It's mainly the ability to resize RAIDZ or RAIDZ2 zdevs that would be really helpful.
Scramblejams 11y ago
Me too. I've added so many drives in onesies and twosies to so many MD RAID5/6 arrays over the years that I simply can't confidently deploy ZFS for that case.
cmurf 11y ago
md RAID will require a lengthy reshape. BTRFS supports adding a new drive, reshape (balance) is optional.
- throwaway7767 11y ago
  > md RAID will require a lengthy reshape Array reshapes are rare, and it'll only use idle IO bandwidth anyway. Redundancy is guaranteed during the whole process. So I don't see this as a problem. > BTRFS supports adding a new drive, reshape (balance) is optional Thanks for pointing this out. I didn't know btrfs supported array reshapes. I'm waiting for it to mature (RAID5/6 was only added in 3.19, for example) but I expect I'll switch over at some point, probably at the point it's considered "boring" (exactly the experience I want from my filesystems).

oskarth 11y ago

Your comment would be more honest if it started with "Things you can't do with GPL".

deleted 11y ago
[deleted]

switch007 11y ago

- Use deduplication in a production environment [1] [1] http://serverfault.com/questions/234475/zfs-destroying-deduplicated-zvol-or-data-set-stalls-the-server-how-to-recover http://serverfault.com/questions/234475/zfs-destroying-dedup...