OpenZFS Developer Summit

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Open-zfs-san-francisco-logo.png The second annual OpenZFS Developer Summit will be held in San Francisco, November 10-11, 2014. All OpenZFS developers are invited to participate.

The goal of the event is to foster cross-community discussions of OpenZFS work and to make progress on some of the projects we have proposed. This 2-day event will consist of 1 day of presentation (Nov 10) and a 1-day hackathon (Nov 11).

Details about registration, presentations, and sponsorship opportunities are provided on this page.



Event Photos

Photos of the event can be viewed on the OpenZFS Google+ page.

Topics Discussed

Title Speaker Slides Video
Keynote Matt Ahrens from Delphix slides video
Platform Overview: ZFS on OSv Raphael Carvalho from Cloudius slides video
Platform Overview: ZFS on Linux Brian Behlendorf from LLNL slides video
Platform Overview: illumos Prakash Surya from Delphix slides video
Platform Overview: FreeBSD Xin Li from iXsystems slides video
Platform Panel Q&A Representatives from participating companies - video
Manta Dave Pacheco from Joyent slides video
Compression Saso Kiselkov from Nexenta slides video
Performance George Wilson from Delphix slides video
Host-Aware SMR Tim Feldman from Seagate slides video
Fast File Cloning Pavel Zakharov from Imation slides video
Device Removal Alex Reece & Matt Ahrens from Delphix slides -
libzfs_core and ioctl stabalization Richard Yao from ClusterHQ slides -
Channel Programs Chris Siden from Delphix slides -
Company Lightning Talk: DDRdrive Chris George slides -
Company Lightning Talk: ClusterHQ Luke Marsden slides -
Company Lightning Talk: Delphix Matt Ahrens slides -
Company Lightning Talk: Coraid Richard Elling slides -
Company Lightning Talk: Storiant John Layman slides -
Company Lightning Talk: Syneto Dan Vatca slides -
Company Lightning Talk: Nexenta Tony Nguyen slides -
Company Lightning Talk: iX Systems Josh Paetzel slides -
Company Lightning Talk: Zacodi Labs Maxim Martynov slides -
Day 1 Closing Matt Ahrens from Delphix - -
Hackathon and Day 2 Closing Hackathon Participants & Matt Ahrens from Delphix - -

Event Logistics


Note: Day 1 and Day 2 of the event will take place in different locations a 10 minute walk apart.

On Monday, November 10, 2014 the event will take place at the Children’s Creativity Museum

221 Fourth Street, San Francisco, CA 94103. Behind the Carousel at the corner of Fourth and Howard.

On Tuesday, November 11, 2014 the event will consist of the hackathon and related activities and will take place at the Delphix San Francisco Office

604 Mission Street, 4th floor, San Francisco, CA 94105


Monday, November 10, 2014

9:00am - 9:30am Breakfast/Registration
9:30am - 9:40am Keynote (Matt Ahrens from Delphix)
9:40am - 10:10am Platform Overview: ZFS on OSv (Raphael Carvalho from Cloudius)
10:10am - 10:40am Platform Overview: ZFS on Linux (Brian Behlendorf from LLNL)
10:40am - 10:50am Platform Overview: illumos (Prakash Surya from Delphix)
10:50am - 11:00am Platform Overview: FreeBSD (Xin Li from iXsystems)
11:00am - 11:30am Platform Panel Q&A (All)
11:30am - 12:15pm Lunch
12:15pm - 12:45pm Manta (Dave Pacheco from Joyent)
12:45pm - 1:00pm Compression (Saso Kiselkov from Nexenta)
1:00pm - 1:30pm Performance (George Wilson from Delphix)
1:30pm - 2:00pm Coffee & Snack Break
2:00pm - 2:30pm Host-Aware SMR (Tim Feldman from Seagate)
2:30pm - 3:00pm Fast File Cloning (Pavel Zakharov from Imation)
3:00pm - 3:30pm Device Removal (Alex Reece & Matt Ahrens from Delphix)
3:30pm - 3:45pm libzfs_core and ioctl stabalization (Richard Yao from ClusterHQ)
3:45pm - 4:00pm Channel Programs (Chris Siden from Delphix)
4:00pm - 4:30pm Coffee & Snack Break
4:30pm - 5:45pm Company Lightning Talks (Various)
5:45pm - 5:55pm Closing (Matt Ahrens from Delphix)
6:00pm - 8:00pm Beer Bash & Casual Dinner

Tuesday, November 11, 2014

9:00am - 9:30am Breakfast
9:30am - 11:00am Hackathon
11:00am - 11:15am Coffee & Snack Break
11:15am - 12:00pm Hackathon
12:00pm - 1:00pm Lunch
1:00pm - 2:30pm Hackathon
2:30pm - 2:45pm Coffee & Snack Break
2:45pm - 4:30pm Hackathon
4:30pm - 5:30pm Hackathon Presentations and Awards
6:00pm - 8:00pm Optional dinner at Thirsty Bear

Location is 5 minute walk from Delphix office.

Email if you are interested.

Note that the optional, off-site dinners on Sunday and Tuesday are at your own expense.


Committed sponsors

Thanks to last year's sponsors who have already committed to sponsoring the 2014 event:

Delphix logo.png Ddrdrive logo dev 2013.png Logo freebsdfoundation.png
Storiant.png Ixsystems.jpg New hac logo.jpg

Thanks to our new sponsors for the 2014 event:

Syneto-logo-Sept14.svg Seagate 2c pos.jpg OmniTI-logo.jpeg

Sponsorship opportunities available

  • Cash donation for miscellaneous expenses (any donation amount would be great!)

Other ways to sponsor

  • Photographing the event
  • Video recording and streaming the presentations

What you get for sponsoring

  • Your name, logo, and link on the event page on
  • Your name, logo, and link on the announcement email (if possible)
  • Mentioned as a thank you during the opening and closing of the event
  • Space to put your pop-up banner at the event
  • An opportunity to be known as a OpenZFS supporter in a very talented and influential community

Funded items

Please send email to admin at open-zfs dot org if you would like to sponsor the event.


The goals of the hackathon are:

  • to get people working with ZFS engineers from outside their normal circles
  • to start work on some of the projects we'd like to accomplish

Therefore, we should plan to work in small teams of 2-3 engineers. The team members could be pair-programming, splitting up the work into discrete tasks for each person, or advising / implementing.

Hackathon ideas

Add your idea and your name below. Be prepared to explain your idea at the beginning of the hackathon and enlist/entice others to help with it.

  • Poor mans compressed send (decomp when recv)
    • Matt Ahrens - Working prototype, some work remains (e.g. send flags)
  • new CLI option to enable send features: zfs send -x embedded,largetblock or -x all
  • Sha 512/256
    • Saso and John Mark - Implemented Blake2 hash instead. Saso also revived a SCSI unmap patch
  • JSON command output
  • File cloning with implicit indirection
  • Rip out scrub throttle, queue mb not ios
    • George Wilson - Mostly finished, needs testing
  • print usage message for specific property
    • zfs help command
  • One man page per subcommand
    • Manoj - Completed this work
  • Channel Programs - continuation of work from last year's hackathon
    • See project page, slides and video describing project
    • Chris and Paul - (Best in show winner) Demo of several working channel programs, lots of testing yet to do.
  • compile ZFS on Linux with -std=gnu99; does it work?
  • storage pool aging
    • specify histogram of free segment sizes
    • allocator chooses locations to satisfy histogram
  • "get next file" syscall
    • iterates in object # order, opening next file; zfs prefetches dnodes
    • could speed up operations that need to operate on every file in a filesystem, e.g. "chmod -r"
  • Porting Party - learn how to contribute changes to a new platform
  • Upstream zfs-make - tool to quickly build zfs on illumos
    • Justin and Andiry - 5 new issues upstreamed for review, including a performance enhancement aggregating sync and async operations
    • Dan McDonald brought zmake to illumos
    • Steve, Chip, Brian B. - Building zfs on illumos
  • performance analytics framework - record performance, store & display (dtrace + graphite?)
  • USE method data collection framework for performance analysis (
  • Illumos grub2
  • Use GRUB2 to boot Linux from a root pool with multiple vdevs (
  • Clean up embedded zil code
  • UTF-8 dataset & poolname (Richard)
  • vdev kstats (Richard)
    • Richard and Dan - Added several new per dataset zil kstats
  • zfs_core collaboration (Richard)
  • collectd agents (Richard)
  • scrub/resilver progress (Richard)
  • promote prefetch reads to sync reads
  • object count per user in DMU
    • Isaac and Manoj - Fully vetted design, and implementation begun.
  • make zfs recv less trusting
  • improve arc_kmem_reap()
    • Tony and George - Made progress on this, as well as improving the amount of memory consumed by arc buf headers when using l2arc.
  • quickly creating fragmented pools
    • Tony and George - Use a passed in histogram to create desired fragmentation level - near code complete
  • raidz1 for single device
  • static analysis tools for zfs
  • dynamic analysis for ztest
  • improved documentation for developing zfs on linux
  • runtime lock analyzer
  • make dtrace probes in linux to work with lttng
  • per zone I/O QoS
  • reconstruct space_maps
    • Albert - Has this nearly working
  • convert AVL trees to B-trees or hash tables
  • large dnodes
    • Ned worked on this, solving several crashes - still testing for edge cases
  • cross platform xattr
  • use refcount_t for v_count
  • open-zfs infrastructure in docker (flocker)
    • Luke - made progress on the mailman and website infrastructure
  • fix OS-2313
    • Bryan Dan and Robert worked on a zil_close/spa_sync race that causes intermittent panics and hangs
  • fix zpool commands hanging when we have suspended pools
    • Don and Brian B. - Created a fix for this bug
  • Data collection using statistical methods for weighting recorded data by arbitrary time range
    • Alex and Prakash - A working demo measuring spa activity
  • Add ziltest to zfstest
    • John and Don - got this working, also added a zpool subcommand to list unused disks.

Harassment Policy

OpenZFS Developer Summit is dedicated to providing a harassment-free conference experience for everyone, regardless of gender, gender identity and expression, sexual orientation, disability, physical appearance, body size, race, age or religion. We do not tolerate harassment of conference participants in any form. Sexual language and imagery is not appropriate for any conference venue, including talks. Conference participants violating these rules may be sanctioned or expelled from the conference at the discretion of the conference organizers.

For information about last year's event, see the OpenZFS Developer Summit 2013 page.