[mwcampbell]

At the risk of reigniting an old flame war, it seems to me that a microkernel in which core OS functions such as process management and the virtual file system are in separate servers would be more complicated than a monolithic kernel. Having device drivers and specific file systems in user space may be useful, though.

[mcintyre1994]

The impression I get (university class on OSes) is that the microkernel/modular approach is more about making it simpler to port than making a specific instance simple? Similarly it'd be less complicated to extend since that's just a case of adding a new loadable module. In terms of a learning OS I'm not sure exactly which should be prioritised - extendability/portability or a simple structure? If this is a topic with a lot of depth I'm obviously not getting I'd definitely be interested in a discussion - my exam is soon :)

[mwcampbell]

Have you read the debate between Andy Tanenbaum and Linus Torvalds from about 1992? It's a discussion of the tradeoffs between microkernels (Tanenbaum) and monolithic kernels (Torvalds). You can find it here:

http://oreilly.com/catalog/opensources/book/appa.html

The chapter by Torvalds in the same book is also worth reading:

http://oreilly.com/openbook/opensources/book/linus.html

The claim that microkernels improve portability makes no sense to me, since Linux itself is very portable, as are the BSDs (especially NetBSD and OpenBSD).

[stplsd]

This is flame between two man with HUGE egos, not a debate.