[pjc50]

> What I would really like to see is a two-tier cache system: most recently accessed files are cached to RAM, with less recently accessed files spilling over to a disk-backed cache. That would open up a world of additional applications whose useful cache size exceeds practical RAM amounts

This is really hard to get right if the origin cloud storage is anything other than immutable. Otherwise you're in for a world of cache invalidation and consistency pain.

I've gradually come round to the other opinion: there should be devices that sit on the PCIe/NVMe bus and provide a blob storage API rather than a block one, and there should be an operating system blob API that is similar to but not identical to the filesystem one.