May OpenZFS Leadership Meeting

Wed May 29 16:15:17 UTC 2019

Thanks everyone who participated in yesterday's meeting.  The video
recording is now up: https://youtu.be/EzyPr3BuePo

The next meeting will be June 25, at 1pm pacific time.

The meeting notes follow:

   -

   Happy ZoL 0.8!
   -

      Lots of downloads and excited people. Successful so far!
      -

   Illumos encryption status (Jerry/Jason/Jörgen)
   -

      Jerry has all of Jörgen’s work pulled over and building on illumos.
      Resolving some test failures and then will put it out for an illumos code
      review.
      -

      The code review will go out to the illumos developer mailing list and
      ask that they identify issues with the platform-dependent changes in the
      port. People will have ample time to comment and raise issues before the
      RTI is submitted.
      -

   RAIDZ Expansion status (Matt)
   -

      Will have an Alpha out this week or next. Pools will need to be
      destroyed if you use it.
      -

      The change lets you add a device to an existing pool and reflows the
      data between disks.
      -

      All of the caveats and details of what does and doesn’t work will be
      included in the PR.
      -

      Call for testing! Once the code is up, any manual testing under
      different workloads and setups will be greatly appreciated. It would also
      be great if people could help write systemic tests.
      -

   BSDCAN update
   -

      The future of ZFS on FreeBSD
      <https://www.bsdcan.org/2019/schedule/events/1060.en.html> (Allan)
      -

         One of the goals of the talk was to motivate the ZFS repo of
         FreeBSD rebasing over ZoL. The advantages of having the
consumers of ZFS
         closer together was highlighted.
         -

         There was some initial pushback people thought that the rebase
         will make ZFS use the Linux Compatibility layer of FreeBSD,
which is not
         the case. Once this was clear, there were no further pushbacks
         -

         Matt brought up that once the rebase is done and stable,
         discussions may be initiated for potentially renaming the ZoL repo.
         -

      snapshot scalability
      <https://www.bsdcan.org/2019/schedule/events/1073.en.html> (Matt)
      -

         Slides are posted and video will be up eventually. Please check
         them out if you’re interested in learning more about snapshots.
         -

         Matt will post a link to #openzfs once he has one.
         -

   DRAID meeting
   <https://docs.google.com/document/d/1SDuFWjiAZbsqJSYOt0iO2Dh4RvU-CzcixtQqLW6TuIw/edit#heading=h.zd12b6w407aq>
   recap (Richard Elling)
   -

      There were about 11 participants
      -

      There is a design doc (linked above) with all the history of its
      edits based on the discussions that took place. Please add
comments to the
      doc to further the discussion.
      -

      There is still work to be done but since the code changes are
      sizeable, we’ll try to split them into individual commits when it makes
      sense.
      -

         Sef says he is available to do reviews at any time, just reach out.
         -

   CoC update (Matt/Karyn)
   -

      Code of Conduct was put into place since the last meeting. We made
      several changes based on community feedback. Thanks for participating!
      -

      We will have a call for nominees for the Working Group in the fall,
      and then will review the CoC at that point and have another community
      comment period. The goal is to complete this before the Dev Summit.
      -

   The Dev Summit is Nov 4-5 in SF. See open-zfs.org
   <http://open-zfs.org/wiki/OpenZFS_Developer_Summit_2019> for upcoming
   dates (e.g., call for presentations).
   -

      Registration opens July 8th
      -

      Send presentations to Matt by August 19th
      -

      Thanks to Datto, Delphix, and Intel for already sponsoring! Reach out
      to @kritter if you want to sponsor and she can give you the details.
      -

   Request from sef! The On-Disk Format
   <http://www.giis.co.in/Zfs_ondiskformat.pdf> document is out of date,
   and doesn’t reflect recent changes (e.g., encryption). It would be really
   helpful to update this and keep it up-to-date going forward (Perhaps in a
   semi-automated way?)
   -

      Tom: The info about how things look today exists in various places,
      so it is just a question of pulling it together into a single place.
      -

      Matt: We only have a pdf for that, and we probably can’t just
      copy-paste it somewhere else. It would be good to have a
document with this
      info. Let’s put out a call for a volunteer to do this.
      -

         Paul pointed out that it is licensed under a Berkeley License
         <https://web.archive.org/web/20120825093052/http://developers.sun.com/berkeley_license.html>
         -

   Compressed arc performance issue - single threaded sequential read
   -

      Sequential reads are decompressed by the (one) user’s thread.
      -

      With non-compressed ARC, they are decompressed by the (several) zio
      threads, leading to more parallelism and improved performance.
      -

      This is a good reason to disable compressed ARC (for workloads with
      single threaded sequential read).
      -

      We could make the prefetches decompress into the dbuf cache, to get
      this performance back.
      -

         If we do that, could we then make compressed ARC mandatory?
         -

         Maybe… but Allan may have found another way to address the problem
         that motivated him to make compressed ARC mandatory
         -

   Please take a look at the redacted send-receive requests as soon as you
   get a chance so we can push this now that 0.8 is out. It’s in sync with 0.8.
   -

   Next meeting will be in 4 weeks: June 25

On Mon, May 27, 2019 at 8:51 PM Matthew Ahrens <mahrens at delphix.com> wrote:

> The next OpenZFS Leadership meeting will be held tomorrow, May 28,
> 1pm-2pm Pacific time.  We don't have much on the agenda for this month, so
> if there are things you'd like to discuss, this is a good opportunity -
> send me an email or edit the doc :)
>
> Everyone is welcome to attend and participate, and we will try to keep the
> meeting on agenda and on time.  The meetings will be held online via Zoom,
> and recorded and posted to the website and YouTube after the meeting.
>
> The agenda for the meeting will be a discussion of the projects listed in
> the agenda doc.
>
> For more information and details on how to attend, as well as notes and
> video from the previous meeting, please see the agenda document:
>
>
> https://docs.google.com/document/d/1w2jv2XVYFmBVvG1EGf-9A5HBVsjAYoLIFZAnWHhV-BM/edit
>
> --matt
>