ZFS: The Last Word in Filesystems


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!



Congratulations Jeff and team. Great work!

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


Posted by Alan Hargreaves on October 31, 2005 at 03:54 PM PST #

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

Posted by Tim Foster on October 31, 2005 at 04:14 PM PST #

Congratulations, Jeff.

Posted by Coy Hile on October 31, 2005 at 05:00 PM PST #

Hooray! Congratulations to all the team. Can't wait to get my mitts on your work!

Posted by Boyd Adamson on October 31, 2005 at 05:24 PM PST #


Posted by Edward Wang on October 31, 2005 at 07:12 PM PST #

Congrats ! That is major progress.

Posted by jake on October 31, 2005 at 07:14 PM PST #


Posted by Jeffrey Olson on October 31, 2005 at 10:33 PM PST #

Congrats! Really looking forward to using ZFS.

Posted by kaiwei on November 01, 2005 at 01:11 AM PST #

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.

Posted by Amit Kulkarni on November 01, 2005 at 07:48 AM PST #

Great news!!

Posted by Rayson (via proxy) on November 01, 2005 at 02:50 PM PST #

Bloody Excellent Team ZFS!

Posted by Al Hopper on November 01, 2005 at 07:33 PM PST #

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!

Posted by David Braun, MultiTask ComputerWorks on November 02, 2005 at 08:17 AM PST #

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. ;-)

Posted by Dermot Canniffe on November 02, 2005 at 07:55 PM PST #

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?

Posted by Ihar Filipau on November 02, 2005 at 10:32 PM PST #

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!

Posted by Anthony Chambers on November 03, 2005 at 03:47 AM PST #

Will linux distributions be able to implement ZFS or is it solaris only?

Posted by ju7uf on November 08, 2005 at 07:04 PM PST #

can any one help me to get technical papers on ZFS

Posted by sreejith d on July 22, 2006 at 09:25 PM PDT #

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