Around a decade ago, I was happy to learn about bcache – a Linux block cache system that implements tiered storage (like a pool of hard disks with SSDs for cache) on Linux. At that stage, ZFS on Linux was nowhere close to where it is today, so any progress on gaining more ZFS features in general Linux systems was very welcome. These days we care a bit less about tiered storage, since any cost benefit in using anything else than nvme tends to quickly evaporate compared to time you eventually...