From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.2 Received: (qmail 25911 invoked from network); 8 Apr 2020 18:51:21 -0000 Received-SPF: pass (minnie.tuhs.org: domain of minnie.tuhs.org designates 45.79.103.53 as permitted sender) receiver=inbox.vuxu.org; client-ip=45.79.103.53 envelope-from= Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with UTF8ESMTPZ; 8 Apr 2020 18:51:21 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id F212E93DBF; Thu, 9 Apr 2020 04:51:13 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id BA4DC93D3C; Thu, 9 Apr 2020 04:50:35 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (1024-bit key; unprotected) header.d=planet.nl header.i=@planet.nl header.b="HdrhSV8D"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 8F92E93D3C; Thu, 9 Apr 2020 04:50:32 +1000 (AEST) Received: from cpsmtpb-ews04.kpnxchange.com (cpsmtpb-ews04.kpnxchange.com [213.75.39.7]) by minnie.tuhs.org (Postfix) with ESMTP id 5455E93D2D for ; Thu, 9 Apr 2020 04:50:30 +1000 (AEST) Received: from cpsps-ews26.kpnxchange.com ([10.94.84.192]) by cpsmtpb-ews04.kpnxchange.com with Microsoft SMTPSVC(8.5.9600.16384); Wed, 8 Apr 2020 20:50:26 +0200 X-Brand: 7abm2Q== X-KPN-SpamVerdict: e1=0;e2=0;e3=0;e4=(e1=10;e3=10;e2=11;e4=10);EVW:Whi te;BM:NotScanned;FinalVerdict:Clean X-CMAE-Analysis: v=2.3 cv=A4b3w5eG c=1 sm=1 tr=0 cx=a_idp_e a=YnLMpE5S06+Zisl5ga1zfg==:117 a=soxbC+bCkqwFbqeW/W/r+Q==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=x1i13A_MHe4A:10 a=IkcTkHD0fZMA:10 a=cl8xLZFz6L8A:10 a=p8hWPCrPAAAA:8 a=1_KLf8pWH2iXmsuzwvkA:9 a=QEXdDO2ut3YA:10 a=hdUzUiK6lsseaELp4_5Y:22 X-CM-AcctID: kpn@feedback.cloudmark.com Received: from smtp.kpnmail.nl ([195.121.84.46]) by cpsps-ews26.kpnxchange.com over TLS secured channel with Microsoft SMTPSVC(8.5.9600.16384); Wed, 8 Apr 2020 20:50:27 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=planet.nl; s=planet01; h=message-id:to:date:subject:mime-version:content-type:from; bh=YXygrLLubjWOWHpLiS3jGJewha72QBaxEvf6wQd291I=; b=HdrhSV8DnZdfAA57gGquc7PvlEMlwg7MwbHAtTxTx08qXjq75EENSxfyx5WMqDCp9V3LWnLamTaoT y5T43hhSpThlYrOnoPwIallCTc4uSHDf/2wvo5PtXgaUIIQJaxffBxNj3g8hMzERSRm4s0Cs8TxUdw R2AWg2Re2vN7BQXw= X-KPN-VerifiedSender: Yes X-CMASSUN: 33|S3tc0gAEFcS7fDykg3oWlXPlfltrjVVssOtpNylGXOUckk4qUPTkaZE9++5LLb0 ETKP80HqBXEp4r3qC7rPG4w== X-Originating-IP: 80.101.112.122 Received: from mba2.fritz.box (sqlite.xs4all.nl [80.101.112.122]) by smtp.kpnmail.nl (Halon) with ESMTPSA id cf474c14-79c9-11ea-bd55-005056ab7584; Wed, 08 Apr 2020 20:50:26 +0200 (CEST) From: Paul Ruizendaal Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) Date: Wed, 8 Apr 2020 20:50:25 +0200 References: <20C3B8BE-E371-4694-8A34-EEC6A5461FAD@planet.nl> <202003291404.02TE4dAI022916@freefriends.org> <2298456D-A786-40C2-9C68-26C99E2002E1@planet.nl> To: TUHS main list In-Reply-To: <2298456D-A786-40C2-9C68-26C99E2002E1@planet.nl> Message-Id: <3FA2A5AF-F4E9-4AD8-9A06-6864DD855498@planet.nl> X-Mailer: Apple Mail (2.3445.104.11) X-OriginalArrivalTime: 08 Apr 2020 18:50:27.0029 (UTC) FILETIME=[918FC850:01D60DD6] X-RcptDomain: minnie.tuhs.org Subject: Re: [TUHS] 8th Edition timeline X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" As was suggested on the list, I=E2=80=99ve reached out to Peter = Weinberger to better understand the time line of the File System Switch = and the 8th edition network file system. He has been very helpful, but = the one line summary is that it is unfortunately too long ago to = remember specific details with any certainty. In general Peter remembers = that he was concerned that the project was too big for one person to do, = and hence always looked for design choices that would leave the work = scope manageable. Time line. Since my last post on this subject I have found that the ACM conference = talk of March 1985 was also held 9 months earlier at a Usenix conference = - leaving a time slot between end of 1981 and summer 1984. Peter vaguely = remembers that the essential ideas were done "before 1983=E2=80=9D. It = would stand to reason that 1983 was spent on getting corner cases of the = network file system right, but all this is no more than plausible = conjecture. File system switch (FSS). The guiding thought for the FSS was to extend the philosophy of = =E2=80=98everything is a file=E2=80=99 to new areas, also other than = network files. Early implementations already included a simple, = read-only =E2=80=98/proc=E2=80=99 file system for example. I asked if = any experiments had been done with virtualising =E2=80=98/dev', but = Peter could not recall any such work. I personally find that the FSS has an elegance that fits with other = parts of Research Unix and asked Peter about its origins. He does not = recall any special "a-ha=E2=80=9D moments, but does recall that the way = it was done just felt natural to him. Other options would have included = to do the switch at the sys call level (which felt too complicated) or = at the block device level (which felt too limited). I also asked about how his reworking of =E2=80=99namei=E2=80=99 and = centralising all namespace operations in that function came about (in my = view it is key to a concise switch). Here, too, it is too long ago to = remember any specifics, but Peter comments that he never liked to write = much code and that spending time on finding ways to make the amount of = coding as small and straightforward as possible would have been in = character. Eighth edition network file system Once the FSS exists, a simplistic network file system is not hard - just = do RPC to a remote server. Peter chose to do a user level file server in = order to keep the work scope and complexity down to manageable levels. = As highlighted in the ACM paper, the devil is in the detail of = replicating all the semantics of normal local disk files. Cases like a = file being kept alive if a process still has it open, the complexities = of cross-mounted network files (let alone recursively mounted), handling = failed connections, etc. were hard to sort out and get right. > On 29 Mar 2020, at 20:12, Paul Ruizendaal wrote: >=20 > On 29 Mar 2020, at 16:04, arnold@skeeve.com wrote: >>=20 >> Paul Ruizendaal wrote: >>=20 >>> Related is the question when the "file system switch" was added. It = must >>> have been later than 1981 and before 1985, but I have not been able = to >>> pinpoint it further. >>=20 >> IIRC there was a "paper" (only an abstract) on the file system >> switch published in a USENIX conference proceedings. That woud help >> trace it down. >=20 > I have that paper (=E2=80=9CThe Unix 8th Edition Network File = System=E2=80=9D), it was presented at a March 1985 ACM conference. = However, there are indications that the roots of the file system switch = existed earlier, possibly much earlier. >=20 > I think Doug McIlroy once described 1973 as a pivotal year for Unix, = with many concepts devised that would blossom in the following 3-5 = years. I=E2=80=99m increasingly tempted to think that Summer =E2=80=9981 = - Summer =E2=80=9982 was a similarly pivotal year. >=20 >> Peter Weinberger, who did it, is at Google; you could ask him >> directly, as well. >=20 > That is a good idea. If someone has the email address I=E2=80=99d = appreciate an off list message. >=20 > Paul