Context Dependent Filesystems were one of those weird, wonderful experiments in Unix' early days that never ultimately escaped its home world. Every vendor Unix had a few. HP were true engineers in those days, so HP-UX had more than a few. But the general corporate attitude toward sharing and standardization was very different. "We want to be standards-based, but we also need some special sauce to differentiate us from the competition."
For example, HP-UX was a BSD-based Unix implementation that tried very very hard to pretend it was UNIX System V (R2/R3). "No, no really! I'm not one of that university kids!" But BSD was a far better foundation, vastly better networking etc., so that's what it was underneath.
Unix of the era was billed as a multi-user shared system, but it wasn't always great at that. It desperately lacked much of the quiet robustness and workhorse-ness of the proprietary minicomputer OSs of the day (e.g. VMS, AOS, HP's own MPE). No vendor did more to fill that gap and make multi-workload a workaday reality. HP added a fair-share scheduler (FSS), the first multi-system high availability clustering in Unix (MC/ServiceGuard), and scores of refinements along the way. As a result, in practice HP-UX was admirably hardened, and it ran more users and more concurrent competing jobs per system than any other Unix system could. Often by a wide margin.
In ~1995 HP doubled down on FSS with Process Resource Manager (PRM), which could guarantee various "shares" (weighted priorities) of total machine resources. First commercial Unix ancestor to today's containers. In production ~6 years before BSD jails and Virtuozzo, ~10 years before Solaris Zones, ~18 years before Docker/Linux containers, and ~20 or more years before container were mainstream production vehicles.
Unfortunately for HP, its workstations (the ones OP acquired) weren't nearly as popular with universities and developers as Sun Microsystems', so you tended to find HP-UX in commercial production—larger servers, more workload, but smaller numbers. And thus smaller ability to promote its innovations or be selected because of them.
Hat tip to steely-eyed missile man Xuan Bui and the many unsung engineering stars of HP in the Unix era.
I would say SunOS (i.e. pre Solaris SysV and not including it) was the quality bearer for UNIX in that era. Particularly once they did the Unified Buffer Cache; HP-UX was never able to accomplish this and it makes it not an ideal file server amongst other problems.
HP-UX 10 and 11 progressively imported more SysV code and lost some of the charm that 9.x has.
I find AIX to be fascinating. Especially 3.x against contemporaries with its LVM, and a pageable kernel. A lot of people have snap judgements against it because they saw 'smit' but don't really understand anything about it.
SunOS evolved to be a great file server and "network computing" server, whereas HP-UX evolved to be a better multi-workload commercial server. Horses for courses—and they often ran on different turf.
You're also right to shout out out some of the other innovators: Data General's DG/UX did a great "let's redesign the kernel for multiprocessing and NUMA." IBM's AIX had kernel threads, pageability, and preemptibility at a time when no one else did (plus JFS, LVM, and eventually LPAR isolation). And Sequent DYNIX/ptx had some impressive multiprocessing (RCU) and large DBMS optimizations very early on. HP was by no means alone trying to engineer away Unix' early weaknesses.
>Unfortunately for HP, its workstations (the ones OP acquired) weren't nearly as popular with universities and developers as Sun Microsystems', so you tended to find HP-UX in commercial production—larger servers, more workload, but smaller numbers
Agreed, the university I worked HP systems cost was the major reason Computing Center Sun was purchased, though we had stray discount price purchased units of almost all vendors too.
We did have one HP 3000/MPE running library VTLS quite long time. I can't remember its exact model any more. But was first 160cm heights rack filling old system and then later replaced with some 9000/E35 matching size smallish (a thick and very heavy PC) size smaller 3000 series box. I did not manage that, but helped its sysadmin with his 9-track autoloader issues couple of times. I would have certainly recycled that tape unit to another use, but it was HP-IB (IEEE 488 / GPIB) connected like whole rack filled with disks all daisy-chained were easy to believe not having been cheap. Too bad it was so hard to get GPIB adapter working with other systems. Those terminals used with MPE having local edit buffer were weird, as was HP Roman character set used. All so well built that was a shame to let the go when VTLS was retired about 30 years ago.
Maths department did have better funding to get few HP-UX running long time. Only HP-UX we had at CC was C160 workstation running OpenView NMS, but that's it.
Yes and commercial side (a telco vendor) I did work customer demanded HP and there were very few Sun servers. It was only used if and when software was not at all available for HP-UX. What I recall Ericsson switching systems tended to come with Sun/Solaris and Lucent 5ESS HP/HP-UX that time.
A friend of mine went SF some conference, I don't recall year. But he came back with HP brand sunglasses which HP gave all visiting their booth and told "Remember, not to look at Sun" :D
There were many early stories about Scott McNealy and his Sun crew going into competitive situations against Apollo, ComputerVision, DEC, HP, Intergraph, Masscomp, SGI, Symbolics, Tektroincs—whoever, really, and there were a lot of whoevers in those days. Competition would argue: "Ours are clearly superior!!" and give a good showing of that. Better networking, display resolution, realtime responsiveness, app performance, rendering speed—whatever metric.
And then Sun would hit back: "Yeah, maybe a smidge better... Not saying it is, but maybe, in an ideal light. On the other hand, with Sun, we cost a lot less. That means you can get 3 or 4 of your engineers empowered with a world-class workstation for every engineer you could with <competitor>." Boom. Those economics were compelling.
It also helped that in those days, Sun workstations became the object of desire for a lot of young developers and engineers, myself included. Sun styled itself into the "it" product.
>Unfortunately for HP, its workstations (the ones OP acquired) weren't nearly as popular with universities and developers as Sun Microsystems', so you tended to find HP-UX in commercial production—larger servers, more workload, but smaller numbers. And thus smaller ability to promote its innovations or be selected because of them.
Columbia University during the 1990s was a SunOS/Solaris shop (and, before then, VAX <https://www.columbia.edu/cu/computinghistory/>). My first year, AcIS (Academic Information Systems, IT for faculty/students) set up a single computer lab in the engineering building <https://cuit.columbia.edu/computer-lab-technologies/location...> with HP workstations. Although they booted into HP-UX and its Motif window manager, MAE provided Mac emulation and, in practice, was usually used because most students were unfamiliar with X Window, of course.
The boxes used the same Kerberos authentication as the Sun systems, so I presume I must have been using context-dependent filesystems for binaries when logging into the systems locally, or when I chose to remote log into one specifically from elsewhere (just for novelty's sake; I preferred the Sun cluster, or the Sun box dedicated to staff use).
MAE—the raison d'etre for the HP boxes—was slow and unstable, and by the time I graduated Macs, I believe, replaced HP, which made the lab consistent with what most of the other computer labs had.
For example, HP-UX was a BSD-based Unix implementation that tried very very hard to pretend it was UNIX System V (R2/R3). "No, no really! I'm not one of that university kids!" But BSD was a far better foundation, vastly better networking etc., so that's what it was underneath.
Unix of the era was billed as a multi-user shared system, but it wasn't always great at that. It desperately lacked much of the quiet robustness and workhorse-ness of the proprietary minicomputer OSs of the day (e.g. VMS, AOS, HP's own MPE). No vendor did more to fill that gap and make multi-workload a workaday reality. HP added a fair-share scheduler (FSS), the first multi-system high availability clustering in Unix (MC/ServiceGuard), and scores of refinements along the way. As a result, in practice HP-UX was admirably hardened, and it ran more users and more concurrent competing jobs per system than any other Unix system could. Often by a wide margin.
In ~1995 HP doubled down on FSS with Process Resource Manager (PRM), which could guarantee various "shares" (weighted priorities) of total machine resources. First commercial Unix ancestor to today's containers. In production ~6 years before BSD jails and Virtuozzo, ~10 years before Solaris Zones, ~18 years before Docker/Linux containers, and ~20 or more years before container were mainstream production vehicles.
Unfortunately for HP, its workstations (the ones OP acquired) weren't nearly as popular with universities and developers as Sun Microsystems', so you tended to find HP-UX in commercial production—larger servers, more workload, but smaller numbers. And thus smaller ability to promote its innovations or be selected because of them.
Hat tip to steely-eyed missile man Xuan Bui and the many unsung engineering stars of HP in the Unix era.