Groups > alt.folklore.computers > #235075

Re: Old commercial UNIX in '26

From	cross@spitfire.i.gajendra.net (Dan Cross)
Newsgroups	alt.folklore.computers
Subject	Re: Old commercial UNIX in '26
Date	2026-06-17 11:49 +0000
Organization	PANIX Public Access Internet and UNIX, NYC
Message-ID	<110u1kp$g8g$1@reader1.panix.com> (permalink)
References	<nnd$6ea886ba$1c547b7f@9c94dd43bc13ac30> <nnd$4682d28c$0d318bf6@b19d6313421837aa> <110rgoc$ldq$1@reader1.panix.com> <wfdYR.493866$_BG8.262449@fx24.iad>

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In article <wfdYR.493866$_BG8.262449@fx24.iad>,
Scott Lurndal <slp53@pacbell.net> wrote:
>cross@spitfire.i.gajendra.net (Dan Cross) writes:
>>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.
>
>The system V  unices had the 's5' filesystem
>(and supported ufs, vxfs, and a few others).

Yeah, `s5` was basically the research filesystem with larger
blocks and a doubly-indirect block or something, right?

vxfs was a commercial thing, wasn't it?  I guess with a clean
DDI/DDK environment you can do things like that out-of-tree.

>SGI had XFS, IBM had JFS which supported journaling, and there
>was the clearcase (MVFS) filesystem as well.

DEC had AdvFS as well, which I think came from MICA.

4.4BSD had a log-structured filesystem and started experimenting
with some Plan 9'ish things.  Soft updates for UFS fixed one of
the major performance complaints for FFS.

	- Dan C.

Thread

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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