From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 6 Dec 2008 15:42:33 -0800 From: Roman Shaposhnik In-reply-to: <15070.1228591717@lunacy.ugrad.cs.cmu.edu> To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Message-id: <284C69AC-98F4-49A9-8857-C48D1E9A64AC@sun.com> MIME-version: 1.0 Content-type: text/plain; delsp=yes; format=flowed; charset=US-ASCII Content-transfer-encoding: 7BIT References: <15070.1228591717@lunacy.ugrad.cs.cmu.edu> Subject: Re: [9fans] (no subject) Topicbox-Message-UUID: 5c38fe26-ead4-11e9-9d60-3106f5b1d025 On Dec 6, 2008, at 11:28 AM, Dave Eckhardt wrote: > More globally, if the high adoption rate of NFS is an argument > in favor of its architecture, It is most definitely not. At least in my opinion. However, adoption is the only thing that I know of that can potentially justify excessive *engineering* complexity. Personally I'd call any system that is overly complex *and* has a low adoption rate (for whatever reason) after at least 5 years of having been exposed to the market place, a theoretical artifact of computer science. The usefulness of which is commonly measured by the number of good CS papers dedicated to studying it. I do understand that for you AFS also has a huge redeeming factor of being useful in solving a particular problem. It is hard to say whether it is the best tool for the job, or the only one (it would be interesting if you answered to Erik's question on this list). But perhaps the difference of opinion here stems from the fact that to *you* it does feel like an "enterprise grade" to me (as an outside observer) the "enterprise grade" must be vetted by the market place. Hence my interest in the adoption rate. > and the low adoption rate of AFS is an argument against its > architecture, > why are you reading a Plan 9 mailing list...? This one is easy: Plan 9 (and 9P in particular) doesn't have to have the redeeming quality of high adoption rate in order to justify an excessive engineering complexity. It is not complex at all. It is small and elegant. Whether that compactness and elegance sometimes prevents it from being considered "enterprise grade" is an open question (at least for me it is). The experience of Coraid suggests that it might actually be a nice tool even for those kinds of problems. >> To some extent, the popularity of NFS (is there any NAS box that >> talks AFS?) and Linux is one big testament to the power of "good >> enough" or "worse is better". >> >> Designing "enterprise grade" things is very hard work. >> Implementing them is even harder. The good news is that it >> pays well. The bad news is that you have to be really brave to >> withstand the fear of being obsolete by changing requirements. > > I don't get this. I don't follow the NFS protocol development > carefully, Just to clarify: this thread is really not about me defending NFS. I can't call it elegant. But I can certainly call it "good enough". So at least it succeeds as a lowest common denominator for data sharing. Well, so far at least. > That is, I think the requirements are *not* changing, but rather > that NFS is slowly realizing that those things *are* requirements. Agreed. And I believe both FSs do miss the point. NFS4 especially so. The question is really not about the most efficient implementation of POSIX filesystem semantics over the network, but rather whether POSIX expectations are reasonable in the first place. Plan 9 was bold enough to simply discount some of those expectations and the resulting system proved to be much better than what a typical UNIX provides these days. Now, what would be really interesting is to see is how the kinds of requirements that pNFS has can be satisfied with Plan9/9P approach. Thanks, Roman.