An NVMe namespace is a quantity of non-volatile memory (NVM) that can be formatted into logical blocks. Namespaces are used when a storage virtual machine is configured with the NVMe protocol and are the equivalent of LUNs for FC and iSCSI protocols.
One or more namespaces are provisioned and connected to an NVMe host. Each namespace can support various block sizes.
The NVMe protocol provides access to namespaces through multiple controllers. Using NVMe drivers, which are supported on most operating systems, solid state drive (SSD) namespaces appear as standard-block devices on which file systems and applications can be deployed without any modification.
A namespace ID (NSID) is an identifier used by a controller to provide access to a namespace. When setting the NSID for a host or host group, you also configure the accessibility to a volume by a host. A logical block can only be mapped to a single host group at a time, and a given host group does not have any duplicate NSIDs.
An NVMe subsystem includes one or more NVMe controllers, namespaces, NVM subsystem ports, an NVM storage medium, and an interface between the controller and the NVM storage medium. When you create an NVMe namespace, you can choose to map an NVMe subsystem to the namespace, as follows:
The NVMe subsystem name is case sensitive. It must contain 1 to 96 characters, and special characters are allowed.
The host OS type that the subsystem is being created on.
The host NVMe qualification name attached to the controller. This column can contain comma-separated values because there can be from one to many hosts attached to a subsystem.