[tw04]

We can agree to disagree.

Your own link states that Sun approached NetApp about patents 18 months prior to the lawsuit being filed (to be clear that was Storagetek before Sun acquired them):

>The suit was filed in September 2007, in Texas, three years ago, but the spat between the two started 18 months before that, according to NetApp, when Sun's lawyers contacted NetApp saying its products violated Sun patents, and requesting licensing agreements and royalties for the technologies concerned.

And there was a copy of the original email from the lawyer which I sadly did not save a copy of, as referenced here:

https://ntptest.typepad.com/dave/2007/09/sun-patent-team.htm...

As for the presentation, I can't find it at the moment but will keep looking because I do remember it. That being said, a blog post from Val at the time specifically mentions NetApp, WAFL, how the team thought it was cool and decided to build your own:

https://web.archive.org/web/20051231160415/http://blogs.sun....

And the original paper on ZFS that appears to have been scrubbed from the internet mentions WAFL repeatedly (and you were a co-author so I'm not sure why you're saying you didn't reference NetApp or WAFL):

https://ntptest.typepad.com/dave/2007/09/netapp-sues-sun.htm...

https://www.academia.edu/20291242/Zfs_overview

>The file system that has come closest to our design principles, other than ZFS itself,is WAFL[8],the file system used internally by Network Appliance’s NFS server appliances.

[throw0101b]

> And the original paper on ZFS that appears to have been scrubbed from the internet mentions WAFL repeatedly (and you were a co-author so I'm not sure why you're saying you didn't reference NetApp or WAFL):

Cantrill was not involved in ZFS, and was not a co-author. Cantrill was involved with DTrace:

* https://www.usenix.org/conference/2004-usenix-annual-technic...

* https://www.cs.princeton.edu/courses/archive/fall05/cos518/p...

And the ZFS paper has hardly been scrubbed given it is widely cited:

* https://www.cs.hmc.edu/~rhodes/cs134/readings/The%20Zettabyt...

And the fact that the ZFS paper cites WAFL is hardly an indication of anything, given that NetApp's patent cites a whole bunch of other patents:

* https://patents.google.com/patent/US5819292#patentCitations

Heck, some of the cited patents were Sun's.

* https://en.wikipedia.org/wiki/NetApp#Legal_dispute_with_Sun_...

[cryptonector]

> The file system that has come closest to our design principles, other than ZFS itself,is WAFL[8],the file system used internally by Network Appliance’s NFS server appliances.

That was unnecessary, but that does not betray even the slightest risk of violating NetApp's patents. It just brings attention.

Also, it's not true! The BSD 4.4 log-structured filesystem is such a close analog to ZFS that I think it's clear that it "has come closest to our design principles". I guess Bonwick et. al. were not really aware of LFS. Sad.

LFS had:

  - "write anywhere"
  - "inode file"
  - copy on write

LFS did not have:

  - checksumming
  - snapshots and cloning
  - volume management

And the free space management story on LFS was incomplete.

So ZFS can be seen as adding to LFS these things:

  - checksumming
  - birth transaction IDs
  - snapshots, cloning, and later dedup
  - proper free space management
  - volume management, vdevs, raidz

I'm not familiar enough with WAFL to say how much overlap there is with WAFL, but I know that LFS long predates WAFL and ZFS. LFS was prior art! Plus there was lots of literature on copy-on-write b-trees and such in the 80s, so there was lots of prior art in that space.

Even content-addressed storage (CAS) (which ZFS isn't quite) had prior art.

[throw0101b]

> I guess Bonwick et. al. were not really aware of LFS. Sad.

They were:

> [16] Mendel Rosenblum and John K. Ousterhout. The design and implementation of a log-structured file system. ACM Transactions on Computer Systems, 10(1):26–52, 1992.

> [17] Margo Seltzer, Keith Bostic, Marshall K. McKusick, and Carl Staelin. An implementation of a log-structured file system for UNIX. In Proceedings of the 1993 USENIX Winter Technical Conference, 1993.

* https://www.cs.hmc.edu/~rhodes/cs134/readings/The%20Zettabyt...