[TUHS] Additional groups and additional directory permissions

Thomas Paulsen thomas.paulsen at firemail.de
Sat Aug 3 05:00:12 AEST 2019


isn't Kirk McKusic a member of our group? Guess he can contribute a lot on this issue.

--- Urspr√ľngliche Nachricht ---
Von: Clem Cole <clemc at ccc.com>
Datum: 02.08.2019 15:28:18
An: Aharon Robbins <arnold at skeeve.com>, Doug McIlroy <doug at cs.dartmouth.edu>
Betreff: Re: [TUHS] Additional groups and additional directory permissions

> The best I can tell/remember is that groups went through 4 phases:
> 1.) No groups (earliest  UNIX) [ I personally never used this except in the
>
> V0 retrocomputing]
> 2.) First group implementation (Thompson) [My first UNIX introduction was
>
> with this implementation]
> 3.) PWB 1.0 (Mashey version) [then saw this post PWB]
> 4.) BSD 4.2 (wnj version) [and lived this transistion]
>
> Each was a little different in semantics.
>
> As Doug mentioned, many sites (like Research) really did not need much and
>
> groups were really not used that widely.   Thompson added something like
>
> the Project number of TOPS and some earlier systems.  Truth is, it did not
>
> help much IMO.   It was useful for grouping things like the binaries and
>
> keeping some more privileged programs from having to be setuid root.
>
> Mashey added features in PWB, primarily because of the RJE/Front end to the
>
> Mainframes and the need to have better protections/collections of certain
>
> items.   But they still were much more like the DEC PPN, were you were
> running as a single group (i.e. the tuple UID/GID).  This lasted a pretty
>
> long time, as it worked reasonably well for larger academic systems, where
>
> you had a user and were assigned a group, say for a course or class, you
>
> might be talking.  If you looked at big 4.1 BSN Vaxen like at Purdue/Penn
>
> State, *etc.*, that how they were admin'd.  But as Doug said, if you were
>
> still a small site, the use of groups was still pretty shallow.
>
> But, as part of the CSRG support for DARPA, there was a push from the
> community to have a list of groups that a user could be a part and you
> carried that list around in a more general manner.   The big sites, in
> particular, were pushing for this because they were using groups as a major
>
> feature.  wnj implemented same and it would go out widely in 4.2, although
>
> >>by memory<< that was in 4.1B or 4.1C first.   It's possible
> Robert Elz
> may have brought that to Bill with his quota changes, but frankly I've
> forgotten.   There was a lot of work being done to the FS at that point,
>
> much less Kirk's rewrite.
>
> But as UNIX went back to workstations, the need for a more general group
>
> system dropped away until the advent widely used distributed file systems
>
> like CMU's AFS and Sun's NFS.  Then the concept of a user being in more
> than one group became much more de rigeur even on a small machine.
>
> Clem
>




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