4 ms·

What really worries me here is compatibility with older pools.I hope they have thought about that as freebsd implementation is here since 2007.

by stiray 6y ago

yjftsjthsd-h 6y ago
It's my understanding that ZFS is backwards compatible forever; old pools are on old versions or have fewer feature flags, but they can still be used without issue.
- stiray 6y ago
  Yes in theory they are but currently syncing pools between linux and freebsd zfs is not possible so I would imagine there are some differences. I have around 12Tb of zraided disk space on freebsd and I hope I will be able to upgrade eventually.
  - moonchild 6y ago
    Eh? I currently share a zpool between linux and freebsd, and it works fine without issue.
    - stiray 6y ago
      Thank you for the info, I wasn't aware of that, the last time I have tryed it didt work (1-2 years back)
      - deleted 6y ago
        [deleted]
      - magicalhippo 6y ago
        ZFS is backwards compatible, not forwards compatible. If you create the pool on pre-OpenZFS FreeBSD, you can use it on Linux, but not vice versa. I just did this with FreeNAS (based on FreeBSD 11) and Raspbian.
        nix23 6y ago
        But if you create the zfs with openzfs on freebsd it's the same version and works: sysutils/openzfs/
        chungy 6y ago
        If you leave "zpool create" to its defaults (enable every feature). There's two levels to consider though if you create a pool with explicit consideration for a system with an older version of ZFS: "-o version" and "-d"/"-o feature@...", both of which can be used to fine tune exactly what the pool can and cannot do. I've made a list to help out doing it between ZFS-on-Linux releases. It shouldn't be hard to look up FreeBSD feature lists and do the same: https://chungy.keybase.pub/zfs-features-table.html https://chungy.keybase.pub/zfs-features-table.html
  - hpcjoe 6y ago
    About 2 years ago, I shared a zpool between Linux, FreeBSD, and SmartOS/Illumos. It generally just worked, no matter where the zpool was created from. People warned me about not enabling specific features, so I simply used defaults to see what would happen. Again, 2 years ago, it just worked.
nix23 6y ago
Yes they care about that, with the pool and filesystem versioning, Michael W. Lucas talks about that in this vid: https://www.youtube.com/watch?v=gmaHZBwDKho https://www.youtube.com/watch?v=gmaHZBwDKho
JackMcMack 6y ago
ZFS has feature flags [1]. If you're carefull not to do 'zpool upgrade' (as this commit message warns) unless you understand the consequences, you can switch between ZFS implementations. [1] http://build.zfsonlinux.org/zfs-features.html http://build.zfsonlinux.org/zfs-features.html You can explicity create a pool with certain features disabled. I'm going to try FreeNAS Core tonight.

What really worries me here is compatibility with older pools.I hope they have thought about that as freebsd implementation is here since 2007.

by stiray 6y ago

What really worries me here is compatibility with older pools.I hope they have thought about that as freebsd implementation is here since 2007.

yjftsjthsd-h 6y ago

It's my understanding that ZFS is backwards compatible forever; old pools are on old versions or have fewer feature flags, but they can still be used without issue.

stiray 6y ago
Yes in theory they are but currently syncing pools between linux and freebsd zfs is not possible so I would imagine there are some differences. I have around 12Tb of zraided disk space on freebsd and I hope I will be able to upgrade eventually.
- moonchild 6y ago
  Eh? I currently share a zpool between linux and freebsd, and it works fine without issue.
  - stiray 6y ago
    Thank you for the info, I wasn't aware of that, the last time I have tryed it didt work (1-2 years back)
    - deleted 6y ago
      [deleted]
    - magicalhippo 6y ago
      ZFS is backwards compatible, not forwards compatible. If you create the pool on pre-OpenZFS FreeBSD, you can use it on Linux, but not vice versa. I just did this with FreeNAS (based on FreeBSD 11) and Raspbian.
      - nix23 6y ago
        But if you create the zfs with openzfs on freebsd it's the same version and works: sysutils/openzfs/
      - chungy 6y ago
        If you leave "zpool create" to its defaults (enable every feature). There's two levels to consider though if you create a pool with explicit consideration for a system with an older version of ZFS: "-o version" and "-d"/"-o feature@...", both of which can be used to fine tune exactly what the pool can and cannot do. I've made a list to help out doing it between ZFS-on-Linux releases. It shouldn't be hard to look up FreeBSD feature lists and do the same: https://chungy.keybase.pub/zfs-features-table.html https://chungy.keybase.pub/zfs-features-table.html
- hpcjoe 6y ago
  About 2 years ago, I shared a zpool between Linux, FreeBSD, and SmartOS/Illumos. It generally just worked, no matter where the zpool was created from. People warned me about not enabling specific features, so I simply used defaults to see what would happen. Again, 2 years ago, it just worked.

nix23 6y ago

Yes they care about that, with the pool and filesystem versioning, Michael W. Lucas talks about that in this vid: https://www.youtube.com/watch?v=gmaHZBwDKho https://www.youtube.com/watch?v=gmaHZBwDKho

JackMcMack 6y ago

ZFS has feature flags [1]. If you're carefull not to do 'zpool upgrade' (as this commit message warns) unless you understand the consequences, you can switch between ZFS implementations. [1] http://build.zfsonlinux.org/zfs-features.html http://build.zfsonlinux.org/zfs-features.html You can explicity create a pool with certain features disabled. I'm going to try FreeNAS Core tonight.