NVM Express 1.2
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1.6.17 namespace
A quantity of non-volatile memory that may be formatted into logical blocks. When formatted, a
namespace of size n is a collection of logical blocks with logical block addresses from 0 to (n-1).
1.6.18 Namespace ID
An identifier used by a controller to provide access to a namespace. The NSID value of FFFFFFFFh is
used to indicate all namespaces. An invalid namespace ID is a namespace ID whose value is zero or
whose value is greater than the value reported by the Number of Namespaces (NN) field in the Identify
Controller data structure. All other namespace IDs are valid. A valid namespace ID that maps to an
attached namespace is an active namespace ID. A namespace shall be attached to a controller before
host software may submit I/O commands for that namespace. A valid namespace ID that does not map
to an attached namespace is an inactive namespace ID. A valid namespace ID becomes inactive when
the associated namespace is detached or deleted.
If Namespace Management is supported then Namespace IDs shall be unique within the NVM subsystem
(e.g., namespace ID of 3 shall refer to the same physical namespace regardless of the accessing
controller). If Namespace Management is not supported then Namespace IDs for private namespaces are
not required to be unique.
1.6.19 NVM
NVM is an acronym for non-volatile memory.
1.6.20 NVM subsystem
An NVM subsystem includes one or more controllers, one or more namespaces, one or more PCI
Express ports, a non-volatile memory storage medium, and an interface between the controller(s) and
non-volatile memory storage medium.
1.6.21 private namespace
A namespace that is accessible by only one controller. A host may determine whether a namespace is a
private namespace or may be a shared namespace by the value of the Namespace Multi-path I/O and
Namespace Sharing Capabilities (NMIC) field in the Identify Namespace data structure.
1.6.22 Runtime D3 (Power Removed)
In Runtime D3 (RTD3) main power is removed from the controller. Auxiliary power may or may not be
provided.
1.6.23 shared namespace
A namespace that is accessible by two or more controllers in an NVM subsystem. A host may determine
whether a namespace is a private namespace or may be a shared namespace by the value of the
Namespace Multi-path I/O and Namespace Sharing Capabilities (NMIC) field in the Identify Namespace
data structure.
1.7 Keywords
Several keywords are used to differentiate between different levels of requirements.
1.7.1 mandatory
A keyword indicating items to be implemented as defined by this specification.
1.7.2 may
A keyword that indicates flexibility of choice with no implied preference.