On Tue, Jul 21, 2020 at 12:23 PM <arnold@skeeve.com> wrote:
Grant Taylor via TUHS <tuhs@minnie.tuhs.org> wrote:

> To me, this makes it fairly self evident that /sbin was originally for
> statically linked binaries.  At least in Linux.

Dunno about that.

I'm skeptical as well.
> Does anyone have any history of /sbin from other traditional Unixes?
> I'd be quite interested in learning more.

/sbin and /usr/sbin came into being in the late 80s when Berkeley
and USG were standardizing on file system layouts for diskless workstations;
Sun and DEC and others were also in on this.

/sbin specifically was meant to hold the executables meant for use by
root that previously had been in /etc along with config files.
(sbin ==> super-user bin.)

/sbin showed up in 4.3-Reno (1990), but wasn't in 4.3-Tahoe (1988). This predates Linux by a year or so.  The changes were due to the filesystem standardization and layout changes prompted by, among other things, diskless workstations as you stated later.  Sun's NFS drove a lot of the adaptation in this area since it quickly became the de-facto network file system (though others did exist).
The idea was that /etc held things specific to a box, while /bin, /sbin,
/usr could be remote mounted from a server.  This is also when /home
came into practice as the place to hold home directories.

This avoided having umpteen zillion copies of the same files
(executables, man pages, libraries, etc.) since they could be mounted
read-only from one or a few servers.  At the time, disk space was not
nearly as cheap as it is now.

A big cost savings in having 20 diskless workstations was that you didn't need the 2-4gb of disks for each individual one, but instead could have one copy of the 100MB-200MB of the core OS. When. X started getting libraries out the wazoo with toolkit wars, it saved even more. IIRC, the Sun 3/50's ethernet port was faster than its disk port, so your diskless workstation could be faster than one with a disk (assuming the network wasn't overloaded).

From an era that will be remembered best by "The network is the connector" corruption of a famous marketing slogan...
This is also when /var came into being for log files and such;
again - it was per machine space, so it lived either on a small disk
in the workstation or on a per-client chunk of space on the server
if the client was totally diskless.

All true.