• ZFS
    October 31, 2005

ZFS: The Last Word in Filesystems

Guest Author


Halloween has been a special day for ZFS since its inception.

On 10/31/2001, we got the user-level prototype working.

On 10/31/2002, we got the first in-kernel mount.

And today, 10/31/2005, we integrated into Solaris. ZFS will hit the street in a couple of weeks via Solaris Express.

We (the ZFS team) will have much more to say about ZFS in the coming weeks. But tonight, I just want to tell you what it was like to drive this thing home.

The ZFS team is distributed: we have people working in Menlo Park, California; Broomfield, Colorado; and several other places. This week, we flew everyone in to Menlo Park and took over a giant conference room.

The first thing you notice is the heat. These rooms are made for 100 watt humans, not multi-gigahertz CPUs and associated paraphernalia. And, like any big company, Sun is all about saving money in the dumbest ways -- like turning off the A/C at night, and outsourcing the people who could possibly turn it back on.

At first, things went pretty well. We comandeered the Nob Hill conference room, which has a long table and lots of power and network taps. We brought in a bunch of machines and created 'Camp ZFS'. Each new box amped up the heat level, to the point that it became difficult to think. So we grabbed a 36-inch fan from one of the labs to get the air flowing. That was a huge help, although it sounded like you were wearing a pair of lawn mowers as headphones.

On Sunday, we plugged in one more laptop. That was it -- we blew the circuit breaker! So here we are, less than 24 hours from our scheduled integration date, and all of our computers are without power -- and the room containing the circuit breakers was locked. (Thanks, OSHA!)

So we took a three-pronged approach: (1) went through the Approved Process to get power restored (ETA: April); (2) hunted down someone from campus security to get us key access to the electrical room (ETA: Sunday night); and (3) sent our manager to Home Depot to buy a bunch of 100-foot extension cords so we could, if necessary, run Nob Hill off of the adjacent lab's power grid (ETA: 30 minutes).

All three came through. We ran half of the load over extension cords to the lab, the other half on the Nob Hill circuit. It took a bit of experimentation to find a load balance that would stay up without tripping the breaker again. Apparently, we had angered it. (Even now, I'm typing this blog entry courtesy of a shiny new yellow extension cord.)

Meanwhile, the clock was ticking.

At the end of a large project like this, it's never the technology that kills you -- it's the process, the cleanup of home-grown customizations, the packaging, the late-breaking code review comments, the collapsing of SCCS deltas, stuff like that. With power back up, we slogged on until about 4AM. Everything looked good, so we went home to sleep. Actually, some people just crashed on the couches in my office, and Bill's office next door.

By 10AM Monday we were back, making sure that all the final tests had run successfully, and working through the last bits of paperwork with the Solaris release team. After five years of effort, it was time to type 'putback'.

Denied! The permissions on a directory were wrong.
Fix them up, try again.

Denied! One more TeamWare directory with wrong permissions. Fine, fix that too.

Last try... and there it goes! 584 files, 92,000 lines of change, 56 patents, 5 years... and there it is. Just like that.

Fortunately we were prepared for either success or failure. We had brought in a massive array of vodka, tequila, wine... you name it, we had it. And not in small quantities.

As I said at the beginning, we'll have lots more to say in the coming days. But right now, it's time to sleep!


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Comments ( 17 )
  • Alan Hargreaves Monday, October 31, 2005

    Congratulations Jeff and team. Great work!

    Look forward to reading more from the team over the next few weeks.


  • Tim Foster Tuesday, November 1, 2005

    (Nice post!) There were a few
    celebrations over in Dublin too
    , many congratulations to all in Camp ZFS!

  • Coy Hile Tuesday, November 1, 2005
    Congratulations, Jeff.
  • Boyd Adamson Tuesday, November 1, 2005
    Hooray! Congratulations to all the team. Can't wait to get my mitts on your work!
  • Edward Wang Tuesday, November 1, 2005
  • jake Tuesday, November 1, 2005
    Congrats ! That is major progress.
  • Jeffrey Olson Tuesday, November 1, 2005
  • kaiwei Tuesday, November 1, 2005
    Congrats! Really looking forward to using ZFS.
  • Amit Kulkarni Tuesday, November 1, 2005

    Congrats to Team ZFS!

    We are all eagerly awaiting to install and try it out in the next Solaris Express, and help to thrash out any remaining bugs.
  • Rayson (via proxy) Tuesday, November 1, 2005
    Great news!!
  • Al Hopper Wednesday, November 2, 2005
    Bloody Excellent Team ZFS!
  • David Braun, MultiTask ComputerWorks Wednesday, November 2, 2005
    Fantastic, Jeff! I added a link to your announcement in the ZFS article at Wikipedia: [http://en.wikipedia.org/wiki/Zettabyte_File_System]. That article is pretty minimal. With the project finished, it would be a really good time for some serious expansion of the article.
    As this news spreads, a lot of people are going to want to find out more. Wikipedia is an open-source reference that is exploding in popularity, and countless people will turn to it in the next few weeks. Would anybody here with some intimate knowledge of ZFS like to expand that article? If so, now's the time!
  • Dermot Canniffe Thursday, November 3, 2005
    Very many congratulations to you and the team Jeff. I know how much of a slog ZFS has been, and I'm certain it will all be worth it. Just hope we don't end up boiling the oceans with all that storage. ;-)
  • Ihar Filipau Thursday, November 3, 2005
    It's nice to hear that UFS is about to be given its due rest.
    Thou I have little question to somebody related to FS development.
    Is there any motion to develop writable file system for portabe media? Read-only media (CD & DVD) for some unknown to me reason have they proper file systems - but writable media (such as memory cards & external hard drives) don't. By default, at moment, FAT12/16/32 is used.
    For how long people will have to live with all those problems inhereted from M$ DOS?
  • Anthony Chambers Thursday, November 3, 2005
    I have a simple question about ZFS that will probably require a less than simple answer. That is, how is ZFS better than the latest inception of XFS? I have a very good friend who used to work as an admin on a huge SGI system who looked over the specs for ZFS and found it to be inferior to XFS. XFS can, I'm told, handle larger files and already supports the various systems in place to prevent data corruption, so (apart from the fact that XFS isn't available on Solaris) how is ZFS better than XFS?
    Oh, the other thing... I mentioned this in one of the web-chats with Jonathan Schwartz and the rest of the Sun top-brass and I got a muffled reply, ie nobody could explain why ZFS was better than XFS, I'm hoping that by giving you more time you could give me a better answer!
    One last thing, I love my SGIs but I also love my Sun, I'm not out to get anyone! Looking forward to seeing what ZFS \*can\* do!
  • ju7uf Wednesday, November 9, 2005
    Will linux distributions be able to implement ZFS or is it solaris only?
  • sreejith d Sunday, July 23, 2006
    can any one help me to get technical papers on ZFS
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