April OpenZFS Leadership Meeting

[Matthew Ahrens]

At today's meeting we covered:

Discussions:

   - Making it easier to port commits from ZoL -> other platforms
   - Enabling compression by default
   - Updating LZ4 implementation

Announcements:

   - DRAID meetup
   - ZoL 0.8 status
   - ZoF (ZoL on FreeBSD) test images
   - Code of Conduct

Video recording available: https://www.youtube.com/watch?v=dIVGGJaZ7zk

The next meeting will be May 28th at 1PM Pacific time (5 weeks from today).

Detailed notes, thanks to Karyn and Serapheim:

   -

   DRAID meetup (Richard Elling)
   -

      This is an all-day workshop for people interested in using and
      developing the feature
      -

      The goal is to finalize the design and start working on it
      -

      May 3 at the Delphix SF office (343 Sansome St, Suite 900, San
      Francisco) at 9am
      -

      Please RSVP so we are sure to have enough space. Reach out to anyone
      on the team over email, Slack (#draid)
      -

      Karyn to set up Zoom
      -

      Richard will pull together an agenda document: remote folks (in
      particular) can add comments and items to the agenda
      -

   ZoL 0.8 status (Brian B)
   -

      Tagged final release candidate last week. FC and soaking since then.
      -

      Please test it as much as possible!
      -

      There are a few remaining bugs they are trying to finish up, but
      there shouldn’t be major changes.
      -

      Also working on documentation
      -

      Hoping to release in 2-3 weeks
      -

   ZoL => FreeBSD: test images available (based on Dec ZoL)! See this
   announcement
   <https://lists.freebsd.org/pipermail/freebsd-stable/2019-April/090915.html>
   for details. Please test it out.
   -

      Allan will cross-post the ZoL on FreeBSD announcement to the openzfs
      list.
      -

      JoshP: The current ZoL-based implementation doesn't have TRIM
      enabled, are we dropping it?
      -

         Darth is waiting for ZoL to reach 0.8 and Delphix to upstream
         their latest features to ZoL before doing a final rebase for release.
         Hopefully in 4-6 weeks.
         -

            This rebase should also include the TRIM changes.
            -

   Any feedback on Porting ZoL commits to other platforms? (Brian B)

Are there things we can do to make this easier? Problems found during
porting?

   -

      Igor: Identify pre-platform features, functions, etc. where things
      have diverged between platforms. How to report issues in a way that
      provides visibility to all of the platforms?
      -

         BB: They’ve tried to keep things consistent with illumos, but have
         likely diverged. Getting some documentation from illumos and
other folks
         would help. Source code? Wiki? Mailing list?
         -

      Jerry J: Has been documenting divergence in the SPL interfaces (that
      he noticed as he was porting from ZoL to illumos) in the  and
can send that
      out to the mailing list and we can figure out a better place to put it.
      -

   Enable compression by default at pool creation (Issue
   <https://github.com/zfsonlinux/zfs/issues/8213>) (kpande)

The idea is to give a better out of the box experience. The downsides are:
potential CPU cost (and write performance due to compressing) and new users
misunderstanding how the space is used in certain cases.

   -

      Igor: There have been issues when root pools are expecting
      compression to be disabled (on SPARC?)
      -

      Allan: This has been the default in FreeBSD installer for ~2 years
      -

      Sef: Boot pools need to be different for each platform, but grub
      doesn’t seem like it needs to be different. Sef supports it being the
      default.
      -

      Compression=on has been the default in FreeNAS for several years; no
      complaints
      -

      *** Someone to take an action item to investigate benefits and
      issues, and write it up? (Matt will put out a call for someone to take
      ownership of this)
      -

   Next meeting: push back 1 week (to May 28)?
   -

      Done!
      -

   Code of Conduct
   -

      Send feedback by Apr 29!
      -

   Allan: Proposal to upgrade the LZ4?
   -

      In general people are in favor of this
      -

      The first step is to just update decompression so people get the
      performance improvements
      -

      Next is the exploration of enabling the compressor potentially with a
      tunable that can fall back to the old decompressor
      -

         The fear is that enabling the new compressor could increase the
         space usage if using nopwrite (e.g. double it for existing snapshots)
         -

      Igor: How stable is LZ4+compression?
      -

      Allan: No known issues that he is aware of.


On Mon, Apr 22, 2019 at 9:00 AM Matthew Ahrens <mahrens at delphix.com> wrote:

> The next OpenZFS Leadership meeting will be held tomorrow, April 23,
> 11am-12noon Pacific time (note the earlier than usual 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 :)
>
> 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
>