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Groups > alt.folklore.computers > #235076
| From | cross@spitfire.i.gajendra.net (Dan Cross) |
|---|---|
| Newsgroups | alt.folklore.computers |
| Subject | Re: Old commercial UNIX in '26 |
| Date | 2026-06-17 12:00 +0000 |
| Organization | PANIX Public Access Internet and UNIX, NYC |
| Message-ID | <110u29j$snt$1@reader1.panix.com> (permalink) |
| References | <nnd$6ea886ba$1c547b7f@9c94dd43bc13ac30> <nnd$4682d28c$0d318bf6@b19d6313421837aa> <110rgoc$ldq$1@reader1.panix.com> <nnd$330d094a$7f573b8a@590899249c30700a> |
In article <nnd$330d094a$7f573b8a@590899249c30700a>, Piper McCorkle <contact@piperswe.me> wrote: >On Jun 16, 2026 at 07:49:16 CDT, "Dan Cross" <Dan Cross> wrote: >> In article <nnd$4682d28c$0d318bf6@b19d6313421837aa>, >> Piper McCorkle <contact@piperswe.me> wrote: >>> On Jun 15, 2026 at 18:55:25 CDT, "Lawrence D´Oliveiro" <ldo@nz.invalid> wrote: >>>> “UFS” is the name for a whole family of filesystems, found among >>>> proprietary Unixes and also the BSDs (where it originated). >>>> >>>> All related, and yet all subtly incompatible with one another. >>> >>> My understanding is that UFS is a retroactive name for the File System >>> introduced by the original UNIX, and every UNIX derivative just tweaked it >>> without regard for compatibility. Essentially, UFS is just a generic term for >>> "this UNIX-like's native filesystem which is probably a descendant of the >>> original UNIX File System." >> >> The original-original Unix filesystem on the PDP-7 was radically >> different from what we know today; the way it worked was kind of >> hard to explain. It's kind of recognizable, but using it feels >> odd. >> >> After they moved to the PDP-11, they did a pretty good >> filesystem that looks an awful lot like what we've got today. >> However, it didn't make particularly efficient use of the disc >> devices of that era, as the filesystem didn't take block >> locality into account when allocating blocks on the physical >> device; this meant you could have logically contiguous data >> in a file that was spread across the platters so that reading >> required doing lots of arm and head movement, which is slow (and >> puts wear and tear on the physical components in the device). >> You could get better efficiency by increasing the logical block >> size used by the FS, but that made inefficient use of storage: >> lots of little files wasted space. >> >> Around the time of 4.1BSD, Kirk McKusick got interested in >> addressing this, and did a new filesystem design that made two >> major changes: first, it introduced a notion of locality into >> the design by providing things called "cylinder groups" and >> (roughly) trying to assign files to CGs so that blocks that go >> into them come from regions of the device that are closer, >> physically, than before. This minimizes seek times. The second >> was to increase block sizes, but also introduce the notion of a >> sub-block "fragment" for the trailing part of a file. Blocks >> can be evenly divided into fragments (the fragment size is some >> power-of-two factor smaller than the block size), and a bitmap >> of fragments available in a block is maintained by the >> filesystem; fragments are only allocated to the last block in a >> file (this reduces the need to seek; blocks are physically >> contiguous on the device) while controlling fragmentation >> (blocks are small enough that you're not wasting space unduly). >> This filesystem became available for production use with 4.2BSD, >> and so is sometimes called, "The 4.2BSD Fast File System". >> >> FFS also went to great lengths to order write operations to the >> file structures on the device so that it could tolerate a crash; >> you might lose some data, but at least the filesystem would be >> consistent on recovery. The `fsck` utility could generally >> repair what might have been damaged. >> >> This was such an improvement over the earlier filesystems that >> most vendors adopted it, and over time, it become referred to as >> "UFS". Of course, each vendor had to pee on it to make it smell >> like their own code, so gradually implementations became >> slightly mutually incompatible. Caveat emptor. >> >> I suppose one could describe UFS as a descendent of the original >> Unix filesystem, but it was sufficiently different that I would >> consider that a bit of a reach. > >Something I love about Usenet - the folks on here generally know a lot more >about the details of computing history than me merely browsing Wikipedia :) >Thanks for the rundown of this history! Sure! But caveat that I'm (highly) fallible; I recommend that you verify against primary sources. :-) Here are a few references: UFS: https://dl.acm.org/doi/10.1145/989.990 FSCK: https://dl.acm.org/doi/10.1145/2560011 Soft updates: https://www.usenix.org/legacy/publications/library/proceedings/usenix99/mckusick.html - Dan C.
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Old commercial UNIX in '26 Piper McCorkle <contact@piperswe.me> - 2026-06-15 08:27 +0200
Re: Old commercial UNIX in '26 mechanicjay@sol.smbfc.net (Mechanicjay) - 2026-06-15 06:57 +0000
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-15 09:25 +0000
Re: Old commercial UNIX in '26 ram@zedat.fu-berlin.de (Stefan Ram) - 2026-06-15 10:01 +0000
Re: Old commercial UNIX in '26 ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2026-06-15 13:39 +0000
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-15 14:06 +0000
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-15 14:36 +0000
Re: Old commercial UNIX in '26 jayjwa <jayjwa@atr2.ath.cx.invalid> - 2026-06-15 11:14 -0400
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-15 15:29 +0000
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-15 16:23 +0000
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-15 16:43 +0000
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-15 19:06 +0000
Re: Old commercial UNIX in '26 Pluted Pup <plutedpup@outlook.com> - 2026-06-16 20:07 -0700
Re: Old commercial UNIX in '26 drb@ihatespam.msu.edu (Dennis Boone) - 2026-06-15 15:16 +0000
Re: Old commercial UNIX in '26 Daniel <me@sc1f1dan.com> - 2026-06-15 07:13 -0700
Re: Old commercial UNIX in '26 mechanicjay@sol.smbfc.net (Mechanicjay) - 2026-06-18 15:47 +0000
Re: Old commercial UNIX in '26 jayjwa <jayjwa@atr2.ath.cx.invalid> - 2026-06-15 11:34 -0400
Re: Old commercial UNIX in '26 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-06-15 23:55 +0000
Re: Old commercial UNIX in '26 Piper McCorkle <contact@piperswe.me> - 2026-06-16 04:50 +0200
Re: Old commercial UNIX in '26 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-06-16 03:34 +0000
Re: Old commercial UNIX in '26 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-16 12:49 +0000
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-16 14:40 +0000
Re: Old commercial UNIX in '26 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-17 11:49 +0000
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-17 13:55 +0000
Re: Old commercial UNIX in '26 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-18 09:52 +0000
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-18 14:45 +0000
Re: Old commercial UNIX in '26 Piper McCorkle <contact@piperswe.me> - 2026-06-16 21:59 +0200
Re: Old commercial UNIX in '26 John Ames <commodorejohn@gmail.com> - 2026-06-16 13:53 -0700
Re: Old commercial UNIX in '26 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-17 12:00 +0000
Re: Old commercial UNIX in '26 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-17 13:21 +0000
Re: Old commercial UNIX in '26 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-15 19:35 +0000
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-15 20:01 +0000
Re: Old commercial UNIX in '26 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-16 12:50 +0000
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-15 22:40 +0000
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-16 09:19 +0000
Re: Old commercial UNIX in '26 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-16 13:00 +0000
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-16 13:44 +0000
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-16 14:47 +0000
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-16 14:59 +0000
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-16 16:24 +0000
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-16 20:19 +0000
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-16 21:27 +0000
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-17 08:44 +0000
Re: Old commercial UNIX in '26 Andy Burns <usenet@andyburns.uk> - 2026-06-16 21:39 +0100
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-16 21:19 +0000
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-16 21:29 +0000
Re: Old commercial UNIX in '26 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-16 12:59 +0000
Re: Old commercial UNIX in '26 Peter Flass <Peter@Iron-Spring.com> - 2026-06-16 07:30 -0700
Re: Old commercial UNIX in '26 "Phigan" <phigan@mutinybbs.com.remove-54f-this> - 2026-06-18 16:28 -0400
Re: Old commercial UNIX in '26 "Kurt Weiske" <kurt.weiske@realitycheckbbs.org.remove-83z-this> - 2026-06-20 08:22 -0700
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-20 18:59 +0000
Re: Old commercial UNIX in '26 "Kurt Weiske" <kurt.weiske@realitycheckbbs.org.remove-jv-this> - 2026-06-28 14:16 -0700
Re: Old commercial UNIX in '26 Bud Frede <frede@mouse-potato.com> - 2026-07-04 14:19 -0400
Re: Old commercial UNIX in '26 Bud Frede <frede@mouse-potato.com> - 2026-07-04 14:08 -0400
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-16 14:51 +0000
Re: Old commercial UNIX in '26 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-16 21:32 +0000
Re: Old commercial UNIX in '26 scott@slp53.sl.home (Scott Lurndal) - 2026-06-17 13:54 +0000
Re: Old commercial UNIX in '26 Bob Eager <throwaway0008@eager.cx> - 2026-06-17 14:21 +0000
Re: Old commercial UNIX in '26 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-06-17 19:35 +0000
[OT] Shifts in type of computing machinery (was: Re: Old commercial UNIX in '26) Nuno Silva <nunojsilva@invalid.invalid> - 2026-06-18 08:56 +0100
Re: [OT] Shifts in type of computing machinery Lars Poulsen <lars@beagle-ears.com> - 2026-06-18 06:37 -0700
Re: [OT] Shifts in type of computing machinery Peter Flass <Peter@Iron-Spring.com> - 2026-06-18 07:57 -0700
Re: [OT] Shifts in type of computing machinery Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-06-18 22:51 +0000
Re: [OT] Shifts in type of computing machinery Peter Flass <Peter@Iron-Spring.com> - 2026-06-19 07:37 -0700
Re: [OT] Shifts in type of computing machinery Piper McCorkle <contact@piperswe.me> - 2026-06-19 18:46 +0200
Re: [OT] Shifts in type of computing machinery Nuno Silva <nunojsilva@invalid.invalid> - 2026-06-20 09:28 +0100
Re: [OT] Shifts in type of computing machinery Lars Poulsen <lars@beagle-ears.com> - 2026-06-19 19:57 -0700
Re: [OT] Shifts in type of computing machinery Daniel Cerqueira <dan.list@lispclub.com> - 2026-06-18 15:27 +0100
Re: [OT] Shifts in type of computing machinery Nuno Silva <nunojsilva@invalid.invalid> - 2026-06-21 09:15 +0100
Re: [OT] Shifts in type of computing machinery Peter Flass <Peter@Iron-Spring.com> - 2026-06-18 07:52 -0700
Re: [OT] Shifts in type of computing machinery Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-06-18 22:52 +0000
Re: Old commercial UNIX in '26 Anthk GM <anthk@disroot.org> - 2026-06-22 19:14 +0000
Re: Old commercial UNIX in '26 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-06-22 22:29 +0000
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