NVMe overview

Some controllers include a port for implementing NVMe (Non-Volatile Memory Express) over fabrics. NVMe allows for high-performance communication between hosts and the storage array.

What is NVMe?

NVM stands for "Non-Volatile Memory" and is persistent memory used in many types of storage devices. NVMe (NVM Express) is a standardized interface or protocol designed specifically for high-performance multi-queue communication with NVM devices.

What is NVMe over Fabrics?

NVMe over Fabrics (NVMe-oF) is a technology specification that enables NVMe message-based commands and data to transfer between a host computer and storage over a network. An NVMe storage array (called a subsystem) can be accessed by a host using a fabric. NVMe commands are enabled and encapsulated in transport abstraction layers on both the host side and the subsystem side. This extends the high performance NVMe interface end-to-end from the host to the storage and standardizes and simplifies the command set.

NVMe-oF storage is presented to a host as a local block storage device. The volume (called a namespace) can be mounted to a file system as with any other block storage device. You can use the REST API, the SMcli, or ThinkSystem System Manager to provision your storage as needed.

What is a namespace and a namespace ID?

A namespace is the equivalent of a logical unit in SCSI, which relates to a volume in the array. The namespace ID (NSID) is equivalent to a logical unit number (LUN) in SCSI. You create the NSID at namespace creation time, and can set it to a value between 1 and 255.