But if your goal is absolute, near-100% reliability, you will eventually have to do something about the kernel. Also, if you look at the design of Minix 3, the

But if your goal is absolute, near-100% reliability, you will eventually have to do something about the kernel. Also, if you look at the design of Minix 3, they do address many of the concerns you mention. There's an infrastructure for checkpointing applications, and a “resurrection” server that acts as a configurable watchdog service for the entire software stack from device drivers to web servers. The real goal of the microkernel architecture is to make these watchdog services as reliable as possible (there's only a few thousand lines of heavily audited code running beneath them). That, combined with user-space device drivers (so faulty hardware or driver code doesn't bring down the whole system) would address most of your concerns. No surprise, that's the path they are headed down. I even see that this release includes a "block device fault injection driver" for simulating hardware failures.