Kanchan Joshi

Zoned Namespaces represent the first step towards the standardization of Open-Channel SSD concepts in NVMe. Specifically, ZNS brings the ability to implement data placement policies in the host, thus providing a mechanism to lower the write-amplification factor (WAF), (ii) lower NAND over-provisioning, and (iii) tighten tail latencies. Initial ZNS architectures envisioned large zones targeting archival use cases.

Storage interfaces have evolved more in the past 3 years than in the previous 20 years. In Linux, we see this happening at two different layers: (i) the user- / kernel-space I/O interface, where io_uring is bringing a low-weight, scalable I/O path; and (ii) and the host/device protocol interface, where key-values and zoned block devices are starting to emerge. Applications that want to leverage these new interfaces have to at least change their storage backends.