Paper Title: Handling Sequential Write Workloads in Mixed NVMe/Hard Drive Systems

Paper Abstract: One problem with having both NVMe SSDs and hard drives in a system is that hard drive workloads are optimized for sequential writes. That is, they are set up to minimize disk head travel time between storage operations. SSDs obviously have no such concept. So, to make the two storage systems compatible and allow data transfers between them, the NVMe specification must include a way to introduce sequential writes. The approach under development is Zoned Namespaces (ZNS), which divide an NVMe namespace into zones, which must be written sequentially. This feature is particularly important for hyperscale sites which have huge numbers of SSDs and HDDs and are constantly moving data between them. ZNS aligns with the models already used in HDDs, and enables a zoned-block storage layer to emerge across the SSD/HDD ecosystem.

Paper Author: Dave Landsman, Director of Industry Standards, Western Digital

Author Bio: Dave Landsman is Director of Industry Standards at Western Digital. A recognized leader in storage standards since 2008, Dave has been an active contributor in many standards organizations, including NVMe, PCI-SIG, JEDEC, SATA-IO, TCG, T10, T13, SNIA, SFF, and USB-IF. He is currently Western Digital’s board representative for NVMe, SATA-IO, and the CompactFlash Association, and chair of the JC64.8 committee and JC424.1 Joint TG in JEDEC. Dave is a principal member of the Western Digital team leading the ZNS initiative in the ecosystem. He has over 30 years experience in the tech industry, including 18 years at Intel, a stint at a startup, and then immersion in the storage world from 2004 onwards at mSystems/SanDisk/Western Digital. He earned a BA in computer science from the University of California, San Diego.