NetApp Sues Sun for ZFS Patent Infringement

This morning, NetApp filed an IP (intellectual property) lawsuit against Sun. It has two parts. The first is a “declaratory judgment”, asking the court to decide whether we infringe a set of patents that Sun claims we do. The second says that Sun infringes several of our patents with its ZFS technology.

How did we get here?

Like many large technology companies, Sun has been using its patent portfolio as a profit center. About 18 months ago, Sun’s lawyers contacted NetApp with a list of patents they say we infringe, and requested that we pay them lots of money. We responded in two ways. First, we closely examined their list of patents. Second, we identified the patents in our portfolio that we believe Sun infringes.

With respect to Sun’s patent claims, our lawsuit explains that we do not infringe, and – in fact – that they are not even valid. As a result, we don’t think we should be paying Sun millions of dollars.

On the flip side, our suit points out that Sun’s ZFS appears to infringe several of NetApp’s WAFL patents. It looks like ZFS was a conscious reimplementation of our WAFL filesystem, with little regard to intellectual property rights. Here’s what creators of ZFS have to say: “The file system that has come closest to our design principles, other than ZFS itself, is WAFL … the first commercial file system to use the copy-on-write tree of blocks approach to file system consistency.” One of the first patents I filed at NetApp describes this “copy-on-write tree of blocks” technique in detail.

We filed suit against Sun because after we pointed out the WAFL patents, their lawyers stopped getting back to us. The first part of our suit is a declaratory judgment. It’s complicated, but the basic idea is that Sun claims we infringe their patents, so we are requesting a trial to show that’s not true. In essence, a declaratory judgment calls their bluff. It allows us to force a legal conclusion, rather than leaving this threat hanging over our heads. The second part is a complaint against Sun for infringing several WAFL patents with ZFS.

As we file this case, I’m painfully aware of the bad feelings that many people have about IP lawsuits. Business people sometimes view them as the last gasp of a dying company, while some technical folks view them as evil under any circumstances. In this case, I doubt that business people will be too concerned, given our growth rate, profitability, and the fact that we are responding to Sun’s claims against us. I expect skeptical technical people to be harder to comfort.

This case is especially sensitive, because Sun has released ZFS as open source. It is admirable to contribute to open source. I have done it personally, although it was a long time ago that I was writing code, and NetApp has also contributed as a company. But it doesn’t help the open source movement to give away code that is encumbered with someone else’s patent rights. The sooner we determine the true status of ZFS, the better it will be for everyone. NetApp certainly doesn’t believe that we can somehow erase every copy of ZFS that has been downloaded. (Impossible!) This lawsuit isn’t about downloads for personal or non-commercial use; it is about what Sun is doing.

We could have a long debate about the merits of the patent system. (I expressed my own qualms here.) But like it or not, it’s the law of the land. Here’s an analogy. Suppose you own a pro football team, and you really believe that touch football would be safer and more humane than tackle. You can lobby all you want to try to change rules, but until you are successful, I recommend that your team keep wearing pads and helmets. NetApp is participating in attempts to reform the patent system, but meanwhile we will play by the rules as they exist.

In closing, let me say that the legal system is a method of resolving disputes between companies, but it does not mean we are “at war”. During this process, we will continue to support all Sun products, including ZFS filesystems that use NetApp storage. It is not in anyone’s interest – Sun’s or ours – to leave a bunch of customers in the lurch. I hope that Sun will respond in kind.

[Note: Sun has now countersued. See Jonathan’s blog post announcing that, and my response.]

Non-technical people can stop reading now.

It is important to me that technical readers not confuse NetApp with SCO, so in our lawsuit, we provided a starting point for people who want to dig deeper. This is not an exhaustive analysis of our case. We simply highlight one particular patent and one particular aspect of ZFS to help people see that this case of infringement is real.

Here’s how the ZFS designers describe filesystem consistency:

The best way to avoid file system corruption due to system panic or power loss is to keep the data on the disk self-consistent at all times, as WAFL does. To do so, the file system needs a simple way to transition from one consistent on-disk state to another without any window of time when the system could crash and leave the on-disk data in an inconsistent state.

In the ZFS paper, search for uberblock, and compare its role in filesystem consistency with the role of the root inode and file system information structure in our patent 5,819,292. Read claim 4 and its descendents, which describe our tree-of-blocks consistency technique. Claim 8 and its descendents describe efficient snapshot creation based on the tree-of-blocks. Some more useful references are here (see pages 7 and 8), here, and here.

We hope that this level of openness will help raise the bar on how people pursue intellectual property suits.

Let me insert the usual legal disclaimer: I’ve quoted our complaint, but beyond that, I won’t engage in any public comment on the technical details of our case while it is pending.

More Links

• Sun's CEO discusses the lawsuit.
• Sun Patent Team Demanded $36 Million From NetApp

Comments

[John]

Perhaps I'm wrong, but this looks much like a case of applying an existing technique to a different medium, without acquiring what would appear to a reasonable person as a non-trivial modification. If it is so, in my opinion it represents the claim of a significant difference between transmitting an electronic signal through a cable or through a wireless medium, such that modulation techniques remain the same. Copy-on-write is a well known technique, and its application is reasonably wide spread.

Genuinely hope for a reasonable resolution to this conflict.

[benr]

I greatly appreciate your openness Dave. While I understand the business aspects of the action, from a technical point of view a legal struggle between WAFL and ZFS, Sun and NetApp, isn't good for the storage community. Many of the issues patented are not unique to either WAFL or ZFS and are commonly taught to CS students these days.

I don't see any good coming to the customers of Sun or NetApp over this. To the share holders of the victor, perhaps, but not the storage community.

I hope that a Win-Win scenario is possible. Sun and NetApp share a special bond, always have and hopefully always will.

[Applicant]

I was set to interview with NetApp for an open position in a few weeks, but now I'm not. I'm a graduate of a top-ten computer science school with a very high GPA and an excellent resume.

So you know that this isn't open source zealotry: I'm interviewing with Microsoft--they haven't yet filed patent lawsuits.

I understand that you're in a difficult position. Sun was doing something that I perceive as underhanded, and you made the obvious move to defend yourself.

On the other hand, lots of people use ZFS, and it's now 'out there.' Suddenly undermining it is going to harm a lot of people, and you have done nothing to mitigate that. Implying that non-commercial use is okay doesn't really solve this problem: harming commercial users is also bad.

I despise the idea of collecting rents, and that's what you're doing here. You must make it clear that this is a conflict between NetApp and Sun that isn't going to harm users, and that isn't about collecting rent on ideas that other people easily could have had.

[patrick giagnocavo]

I can't see a positive outcome to this litigation, unless it is simply meant as a way to bring Sun to the table; or you are trying to get bought by a larger company.

Sun bought StorageTek, founded in 1969 - you mean to tell me that STK had no prior art in file systems when they have been shipping disks since the mid-70s? They had a virtual disk product with snapshots 4 years before you filed your patent.

Even if NetApp wins, they still lose - the loss of goodwill will far outweigh any monetary gain.

[psa]

Dave,
I'd also like to push the idea of you and Jonathan sitting down over ${favorite_drink} and talking this through.

You're both great companies with nothing to gain from this action.

[trasz]

IIRC the copy-on-write was first used in LFS, not WAFL.

[Ammar Zolkipli]

I must say that I'm quite sad that such events have happened. It's almost like seeing two close friends fighting each other over a small thing. Why can't we all just get along?

I am unfortunately on the fence on this one. I like both companies, as BOTH SUN and NTAP technology and achievements have influenced my educational and professional years. To some extent it does affect me personally that two of my 'technical cornerstones' are in a conflict.

[Winfried Neessen]

Anyhow I see you point of feeling "hurt" by SUN's lawyers I absolutely scorn the idea of lawsuits about software patents. Though you are mentioning that non-commercial users will not be hit- what about the commercial users?

Aren't the commercial users of ZFS, as well the users that are buying your Storage arrays, to combine the best technologies to get best efforts out of it? Aren't the commercial users, the users which are making your revenue grow?

I absolutelly don't think that this is the right way. Hopefully this will find a good end though.

[Serge Wroclawski]

The issue for many of us who see this as a very bad move on NetApp's part has little to do with the technical issues, and more to do with the way in which NetApp is handling the patent issue, which is repeated in your blog.

It is quite common for companies to have large patent portfolios and when products compete, to sign an agreement between the two parties to allow use of patents between them- a sort of treaty.

In your blog you say that your concern isn't personal or non-commercial use, but you neglected to talk about third party commercial use.

If NetApp doesn't want to be seen as a bad actor, then it should work with the various entities (the Freedom Law Center, for example) to have patent indemnity to all parties other than Sun over any patents in ZFS.

[Aidan Thornton]

I just discovered that there was a a very nice Linux filesystem called Tux2 that was abandoned due to Network Appliance's patents. Apparently, the author came up with the idea behind it and implemented it back in the late 1980's. He then decided to base a Linux filesystem on it a few years ago. After someone pointed out that it was similar to NetApp's patents he essentially dropped the project. This is why software patents don't work. (On the other hand, I can see why they'd want to patent it, and it looks like they have good reasons for suing Sun.)

[Leishirsute]

Dave,
Sun doesn't make a compelling distinction between WAFL and ZFS in this Q&A.

ZFS has always "smelled" like WAFL. The documents in the lawsuit really reinforce that.

[Leishirsute]

Oops. Here's the Q&A url
http://www.sun.com/emrkt/campaign_docs/expertexchange/knowledge/solaris_zfs_compat.html#8

[Harold]

Needless to say Sun has a rather different story about how this came about, and I'm certainly not going to automatically take your word on it.

Let's see what falls out when this gets the Groklaw treatment: while I'm sure PJ would have preferred a break now that SCO vs. The World is all but over, this case, which is described in ComputerWorld as "likely [to] become the major test case for open-source software this decade", will become a or the major focus of that community. I doubt you will enjoy that sunshine.

In the meanwhile, I don't think you have the slightest idea how much programmers UTTERLY despise the current use of the US patent system with software: it is an EXISTENTIAL threat to our calling and livelihood. You do us no favors by playing this game, and as already noted above, it will hurt you---I would no sooner associate with a NetApp programmer than I would one working for the [fill in the blank with your preferred odious organization].

Does anyone care to take bets on whether NetApp will by the middle of the next decade be staked out on a barren desert plain next to SCO, a stark object lesson to others who are tempted to compete in the courtroom instead of the marketplace?

[jb]

see jonathan schwartz's reply to this here:

http://blogs.sun.com/jonathan/entry/on_patent_trolling

[Kevin]

That it has taken NetApp this long, given the (apparently) flagrant examples is a bit odd. Was the goal to let Sun get far enough along with FISH to ensure an encumbered ZFS would be particularly expensive?

[TM]

Fazal Majid wrote, "And to think I once actually liked NetApp as a company...
You can kiss my business good-bye. I am adding NetApp to my list of companies to shun, along with SCO and Sony. I am deleting any testimonials I ever put online for your products, and will contact your marketing department shortly to make sure they delete my reference for the S500...."

Interestingly, back in December of 2006, Mazal had this to say about ZFS: "It's mostly a straight rip-off of NetApp's WAFL, but that's a good thing. I run ZFS on my home Solaris/x86 server already...." (http://sayspy.blogspot.com/2006/12/looks-like-zfs-might-be-coming-to-os-x.html)

I guess one could hardly expect a positive response from someone who views using a product that is a "straight rip-off" of another as being "a good thing".....

[bk]

After reading both blogs (yours and Jonathan's) it is clear there won't be a winner. The PR is going to hurt both sides, but as the details are being revealed, its clear that Net Apps is desperate. It all started because Sun bought Storage Tek before Net Apps could, so then you couldn't buy/own their patents. Now Sun won't sell them. But you make it sound like Sun came after you, however its more along the lines that you knew that Net Apps had used the patents but didn't want to pay license fees, so instead you'll try to sue it out of them. And the idea of suing for copy-on-write is like suing for using hash tables. Its been around forever and as TimC stated, I'm sure it will be easy to find prior works.

So unfortunately, this is going to stifle progress in the storage technical arena until the lawyers make their millions.

[JohnQ]

I'm not jumping to any conclusions until more information is available, but at first blush this seems little more than an attempt by NetApp to spread FUD against Sun/ZFS.

It is no secret that Sun's "Thumper" box utilizing ZFS is a direct and significant threat to the high-priced status quo storage vendors like NetApp, EMC, etc. Perhaps NetApp feels the best "competitive" strategy to counter the (real or imagined) threat to their FY08 sales projections is to neutralize ZFS with the spectre of a patent lawsuit. While the technical details may be different, this smells like "SCO vs. The World" rev. 2.0 to me.

As an aside, if those evil Sun engineers really were stealing NetApp IP while developing ZFS, why the numerous acknowlegements in their design docs that some of the concepts in ZFS are similar to WAFL? Why draw unnecesary attention to the the IP you were supposedly trying to rip-off?

[Rene]

I don't see how this can possibly have a positive outcome for NetApp or Sun or their customers no matter who "wins" the case. You say that you're not worried about business people potentially looking at this move negatively given NetApp's growth prospects, but how can it possibly help those very same prospects if you've now alienated so many technical people who feel so strongly against such patent trolling?

I would think a smart business person as a potential or existing customer would understand that it's all those technical people out there that tinker and gain experience with new technologies from their own interest whose worthy elements make their way back to business people as recommendations and solutions to regular business problems. If you've conceded that the technical community is not likely to see this act positively--and you'd be correct--then you've just shut the door on a large number of prospective buyers of your products, haven't you? You must have extreme confidence in your sales force and their C-level contacts since you will now have to rely on them so much more now.

You say: "[This lawsuit] is about what Sun is doing." You've just now educated a lot of your customers about what Sun "is doing" in the marketplace. And as a result they might now take a closer look at Sun's Solaris ZFS and Thumper storage/compute products. Again, how does this suit positively affect the long-term growth prospects of NetApp?

[Mark Buckingham]

From a first reading, this seems like a 'sniping" contest, where one entity says you've been using my stuff, so it's about time you gave me some money. And, the other side saying "no, I'm not, but since you swung at me, I'm going to try and swing at you. Quite childish, if you ask me. We're more civilized than that, aren't we? I'm a firm believer that you don't need to screw the other party over to make money, in this world(although, that wasn't always the case), and I have built my reputation on integrity. Integrity works! This "open" buzz stuff is fun, but in reality, or in business, anyways, it's not always the best choice, unless you want to use it as your charitable side. Sorry, to put off you open sourcers. Some people claim that open source is the sole cause of innovation, but when it comes down to it, it's capitalism. Why would I want to come up with something or work on something that innovates, if I don't stand to make some money off of it...I'm not that much of a sucker. I think Jonathan preaches to the choir a little too much on the "open" thing, personally. In reality, myself as a business guy(and CEO) don't mind paying money for software, if you can show me how it's going to make me money or increase my efficiency. In other words, I'm not a freegan or freeloader, just a no-nonsense businessman(and ocasional programmer:)). The solution to this mess? If I was Dave, I would matter-of-factly, lay down that ZFS uses WAFL technology. I won that technology, please stop using it, or pay me some money. I'm not going to gouge you, or rip you off, or claim that you are ripping me off, just making money from something that I own, while at the same time making sure you make money for what you are paying me for. I think that's the intent of Dave, anyways, by not going after non-commercial users. If you are making money off something that you are using for free, then you should at least toss a token payment for the creator of what you are using. That's just one programmer to another. Failing this, THEN this is when I would go the court method, only after exhausting all other options. The court system should not be used as a tit-for-tat playground. Also, I would ask Jonathan to please explain how we were using what Sun considers their property. If I could honestly, in my herat, say that this was not true, then I would not feel that I owed Sun any money, but if I was using their property, then, well you know. Integrity! It doesn't matter if you CAN get away with something, it's whether you try to get away with something. That's called class. That's why I choose Sun, because they are a class act. Is Netapp a class act?...~Mark~