Groups > alt.folklore.computers > #235087

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	2026-06-18 09:52 +0000
Organization	PANIX Public Access Internet and UNIX, NYC
Message-ID	<1110f4i$42r$1@reader1.panix.com> (permalink)
References	<nnd$6ea886ba$1c547b7f@9c94dd43bc13ac30> <wfdYR.493866$_BG8.262449@fx24.iad> <110u1kp$g8g$1@reader1.panix.com> <hHxYR.91908$tRR9.48494@fx23.iad>

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In article <hHxYR.91908$tRR9.48494@fx23.iad>,
Scott Lurndal <slp53@pacbell.net> wrote:
>cross@spitfire.i.gajendra.net (Dan Cross) writes:
>>In article <wfdYR.493866$_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?
>
>Yep.  And a 14-character filename length limit.

So inodes were still limited to 16 bits?  Yikes.  You think they
could have at least gone to 28 char limits for the filename and
4 byte inode numbers.  :-)

	- 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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