Without getting too much into the details of the system, our durable cache is designed for 5 9s of durability (and we're working on a version that will provide

Without getting too much into the details of the system, our durable cache is designed for 5 9s of durability (and we're working on a version that will provide 11 9s of durability soon). You can't achieve those durability numbers on a single attached NVMe device without some kind of replication.