Sorry, didn't mean to minimize the task here but what you just described is still a pagefile - tiering data according to usage patterns and placing it onto diff

Sorry, didn't mean to minimize the task here but what you just described is still a pagefile - tiering data according to usage patterns and placing it onto different media with varying latency and throughput characteristics is a concept nearly as old as storage. It's cool that Google has made it Borg compatible, but it's also not exactly a breakthrough concept.