Yeah totally valid implementation of which there have been a great many attempts, far too many to list here.
Precisely none of them in 3-5 decades has managed to deliver on the promise of microkernels prompting the question:
"Were huge microkernel advantages actually greatly oversold, is posix a massively debilitating factor that prevents microkernel based systems from delivering on their raison d'etre or was every single one of those implementations a poor one? [1]"
Eh, stuff like older vxworks plays loose and fast with the term microkernel that wouldn't fly today. I don't even think they try to claim that it is one anymore until their most recent release where they actually added (optional) process isolation.
Microkernel as cpu architecture abstraction layer. Such are only accidentally microkernels and not OSes at all as i understand them. They deliver on what of all those wonderful lists of microkernel benefits?
The POSIX layer of QNX is almost exclusively a (collection of) optional services or wrappers in userspace. In what way is it a failure or a poor implementation of a microkernel?
It's an inferior implementation of posix that does not display all those wonderful microkernel os benefits. If it did, we'd hardly be using competing OSes that are insecure, unstable, big-ridden etc. etc. I've never heard of a webserver running on QNX with an enhanced security benefit as a result, have you?
I work at QNX. Of course I've heard of webservers running on QNX with enhanced security as a result. I suspect the lack of widespread use of QNX is because it's a costly, commercial, and not marketed toward personal or cloud computing and not due to technical issues. Marketing trumps technical when it comes to purchasing decisions.
There are plenty of cases in the world where security trumps cost by a massive, massive amount. Not sure why you're talking about personal cloud computing, probably not interesting there.
How many licenses have you sold for this? How secure is it? Got any kind of metrics to share there?
In the past every single time I've probed claims about QNX (claims not made by QNX themselves at all, I hasten to add) as the example of delivering on the promise of microkernel OSes they have turned out to be unsubstantiated.
Needless to say if, you can substantiate them that would be utterly fantastic! Also a massive, massive marketing opportunity I would have thought. Link us up!
Precisely none of them in 3-5 decades has managed to deliver on the promise of microkernels prompting the question:
"Were huge microkernel advantages actually greatly oversold, is posix a massively debilitating factor that prevents microkernel based systems from delivering on their raison d'etre or was every single one of those implementations a poor one? [1]"
[1] including QNX