NVME(4D) Devices NVME(4D)

nvmeIntel NVMe compliant storage driver

The nvme driver uses the blkdev(4D) framework to provide access to NVMe compliant solid-state storage devices. All NVMe version 1.x and 2.X devices are supported.

NVMe devices supporting multiple namespaces will present each namespace as its own blkdev(4D) instance in the system.

The nvme driver can be configured by defining properties in the nvme.conf file. The parameters are considered an unstable interface, subject to change without notice. The following properties are currently supported:

strict-version
This can be set to 0 to allow nvme to attach to devices supporting newer version of the NVMe specification. The default value is 1, limiting nvme to work with devices that support major version 1 or 2.
ignore-unknown-vendor-status
This can be set to 1 to allow nvme to continue operating even if it receives an unknown vendor command status.
admin-queue-len
This is the number of entries in the admin command queue. Legal values are between 16 and 4096, the default value is 256.
io-squeue-len
This is the number of entries in each I/O submission queue. Legal values are between 16 and 65536, the default value is 1024.
io-cqueue-len
This is the number of entries in each I/O completion queue. Legal values are between 16 and 65536, the default value is 2048. When the number of submission and completion queues are the same, the queue lengths will be both set to the lesser of io-squeue-len and io-cqueue-len.
async-event-limit
This is the maximum number of asynchronous event requests issued by the driver. Asynchronous events are used to report error conditions. The driver will never use more asynchronous events than this value, or what the hardware supports if it is less, or 1/10th of the admin queue length if it is less.
volatile-write-cache-enable
This property can be set to 0 to disable the volatile write cache, if the hardware supports it. The default setting is 1, which enables the volatile write cache.
min-phys-block-size
This is the minimum physical block size that is reported to blkdev(4D). This value must be a power of 2 greater than or equal to 512. If the device reports a best block size larger than what is specified here the driver will ignore the value specified here.
max-submission-queues
This is the maximum number of submission queues the driver will create per device. Legal values are between 1 and 65535, the default is to match the number for max-completion-queues. The number of queues created will not be allowed to exceed the drive's hardware limitation. If the number of submission queues is larger than max-completion-queues the completion queues will be shared across the submission queues.
max-completion-queues
This is the maximum number of completion queues the driver will create per device. Legal values are between 1 and 65535, the default is to match the number of interrupt vectors allocated to the drive. The number of queues created will not exceed the number of interrupt vectors, max-submission-queues, or the drive's hardware limitation.

In addition to the above properties, some device-specific tunables can be configured in nvme.conf using the nvme-config-list global property. The value of this property is a list of triplets. The formal syntax is:

nvme-config-list ::= <triplet> [, <triplet>]* ;
<triplet> ::= "<model>" , "<rev-list>" , "<tuple-list>"
<rev-list> ::= [<fwrev> [, <fwrev>]*]
<tuple-list> ::= <tunable> [, <tunable>]*
<tunable> ::= "<name>" : "<value>"

The <model> and <fwrev> are the strings that are returned in the "Model Number" and "Firmware Revision" fields, respectively, in the "Identify Controller" data structure as returned by the "IDENTIFY" command. Specifying a <rev-list> is optional, an empty string ("") may be used instead.

The <tuple-list> contains one or more tunables to apply to all controllers that match the specified model number and optional firmware revisions. Each <tunable> is a <name> : <value> pair. Supported tunable names are:

ignore-unknown-vendor-status
Similar to the global property, this property accepts a boolean value specified as either "on", "off", "true", or "false" to enable or disable the driver continuing operation even if it receives an unknown vendor command status from a controller.
min-phys-block-size
Same as the global property, this is the minimum physical block size that is reported to blkdev(4D). This value must be a power of 2 greater than or equal to 512. If the device reports a best block size larger than what is specified here the driver will ignore the value specified here.
volatile-write-cache
Similar to the global property volatile-write-cache-enable, this property accepts a boolean value specified as either "on", "off", "true", or "false" to enable or disable the volatile write cache, if the hardware supports it. By default the volatile write cache is enabled.

/dev/dsk/cntnd0sn
Block device minor nodes.
/dev/rdsk/cntnd0sn
Raw block device minor nodes.

In the device minor nodes, the following substitutions may occur:

cn
A controller number, typically one for each nvme device found. Controller numbers are dynamically assigned by the system.
tn
The target number. This is the namespace EUI64 if available, or the namespace ID used by the hardware. Namespace ID 0 is reserved, hence target numbers start with 1.
sn
This is the number, representing a subset of the disk. See dkio(4I).

blkdev(4D)

August 27, 2023 OmniOS