NVM Express Announces NVMe 2.0 Specifications with HDD Support

NVM Express has announced the 2.0 generation of NVMe specifications. It involves a set of specifications, which add some new features to the protocol, such as Zoned Namespaces and hard drive support.

The technical working group has overhauled the structure of the various specifications in the 2.0 version so that it is scalable and manufacturers can develop products with support for the protocol faster and easier, the organization behind NVM Express writes.

The specification is divided into those for the basics of NVMe, those for command sets, specifications for the transport of data, such as via PCIe, fiber, RDMA or TCP, and those for the NVMe management interface.

There is a new command set specification for Zoned Namespaces and it allows an SSD and host to work together in placing the data. Aligning that placement with physical location on a storage device can improve performance and increase the storage capacity available to a host, NVM Express said.

Also new is the command set for Key Values, which allows SSD controllers to access data on the basis of key pairs instead of block addresses. It eliminates the overhead associated with translating the keys and logical blocks, and allows apps to communicate directly with the drive.

NVMe 2.0 further provides enhanced support for managing Endurance Groups, a data center technique for merging SSD storage for management capabilities. Finally, NVMe 2.0 provides explicit support for what the NVM Express organization calls “rotating media,” or hard drives. This means that users can replace older protocols such as iSCSI and manage their storage pool entirely via NVMe, but as AnandTech points out, the question is whether hard drive manufacturers will make the switch from SAS or SATA to PCIe.

Incidentally, many of the changes 2.0 brings are extensions or improvements to functions that were already introduced with NVMe 1.4. It is not yet known when products based on the NVMe 2.0 specification will appear.