What is NVMe:

NVMe (nonvolatile memory express) is a new storage access and transport protocol for flash and next-generation solid-state drives (SSDs) that delivers the highest throughput and fastest response times yet for all types of enterprise workloads.

NVMe (non-volatile memory express) is a host controller interface and storage protocol created to accelerate the transfer of data between enterprise and client systems and solid-state drives (SSDs) over a computer's high-speed Peripheral Component Interconnect Express (PCIe) bus.

Help deliver a high-bandwidth, low-latency user experience, the NVMe protocol accesses flash storage via a PCI Express (PCIe) bus, which supports tens of thousands of parallel command queues and thus is much faster than hard disks and traditional all-flash architectures, which are limited to a single command queue.

How NVMe works

NVMe maps I/O commands and responses to shared memory in a host computer over the PCIe interface. The NVMe interface supports parallel I/O with multicore processors to facilitate high throughput and mitigate central processing unit (CPU) bottlenecks.

NVMe supports 64,000 commands in a single message queue and a maximum of 65,535 I/O queues. By contrast, a SAS device typically supports up to 256 commands, and a SATA drive supports up to 32 commands, in one queue.

Benefits of NVMe for Data Storage

· Unlike protocols designed in the days of mechanical hard disk drives, NVMe leverages not just solid-state storage, but also today’s multicore CPUs and gigabytes of memory.
· NVMe storage also takes advantage of streamlined command sets to efficiently parse and manipulate data.

NVMe Use Cases

· Real-time customer interactions such as finance, e-commerce, and software sales agents
· Artificial intelligence (AI), machine learning (ML), big data, and advanced analytics apps
· DevOps, enabling you to run more iterations in less time

NVMe over Fabrics (NVMe-oF)

NVMe is more than faster flash storage – it’s also an end-to-end standard that enables vastly more efficient transport of data between storage systems and servers.

· NVMe over Fabrics extends NVMe’s performance and latency benefits across network fabrics such as Ethernet, Fibre Channel, and InfiniBand.

· Provides higher IOPS and reduced latency from the host software stack all the way through the Data Fabric to the storage array.

NVMe over Fibre Channel (NVMe/FC)

With the recent release of NetApp^®ONTAP^®, NetApp’s data management platform provides NVMe over Fibre Channel support today.

Applications such as databases run much faster when using the NVMe/FC protocol compared to FCP (SCSI protocol with an underlying Fibre Channel connection). ONTAP NVMe/FC traffic can co-reside with FCP traffic on the same Fibre Channel fabric, so it’s easy to get started with NVMe/FC. For many customers with ONTAP AFF systems, this is simply a nondisruptive software upgrade.

Considerations for FC-NVMe configurations

Beginning with ONTAP 9.4, the non-volatile memory express (NVMe) protocol is available for SAN environments. FC-NVMe allows you to run NVMe over an existing FC network with an AFF system. FC-NVMe uses the same physical setup and zoning practice as traditional FC networks but allows for greater bandwidth, increased IOPs and reduced latency than FC-SCSI.

Beginning with ONTAP 9.5 multipath HA pair failover/giveback is supported for NVMe configurations.

Path failover/giveback is not supported in ONTAP 9.4.

NVMe can be the only data protocol on the storage virtual machine (SVM).
FC-NVMe can be the only data protocol on data LIFs.
Only one host can be configured per subsystem.
LUNs and namespaces cannot be mixed on the same volume.
You should configure one management LIF for every SVM supporting SAN.
Cascade, partial mesh, full mesh, core-edge, and director fabrics are all industry-standard methods of connecting FC switches to a fabric, and all are supported.

A fabric can consist of one or multiple switches, and the storage controllers can be connected to multiple switches.

In ONTAP 9.4, only one FC-NVMe data LIF can be configured per SVM.

In ONTAP 9.5, four FC-NVMe data LIFs can be configured per SVM

Create a SVM with NVMe Protocol only.

Enable the Protocol Service.

Check the status of NVMe Protocol service on SVM.

In ONTAP 9.5, four FC-NVMe data LIFs can be configured per SVM.
List the NVMe LIF's.

List the Subsystem.

To add a Host NQN to an existing subsystem.

Listing the NVMe Interfaces.

Listing the Namespaces.

Creating a namespace with size and Host type. But It is not mapped to any subsystem.

Creating new subsystem with OSType VMware.

Add the HOST NQN to the subsystem.

List the name and notice that it is not mapped to any subsystem.

Now Map the Namespace to an existing subsystem.

After this command, namespace is mapped to the subsystem. Now it is ready to discover the disk from host.