It disgusts me, when I see UNIX weenies argue it's actually a good thing UNIX can't do something, and we don't want or need it anyway. Anyway, it's clear to me that the very idea of a filesystem is part of the issue. When I read of the Hydra system, with a file able to protect itself, I noticed that's just an object. Why have a filesystem, when a sea of persistent objects is a much nicer way to think about it?
The notes on the Xerox system labelling each block is neat. I'd wondered how to get reliability in longterm storage, and marking each unit of the disk hadn't occurred to me, but repeating the metadata across the disk had. It's akin to the difference between C and Lisp, where Lisp knows what everything in memory is, and C doesn't.