NVMEADM(8) Maintenance Commands and Procedures NVMEADM(8)

nvmeadm — NVMe administration utility

nvmeadm -h [command]

nvmeadm [-dv] list [-c] [-p -o field[,...]] [ctl[/ns][,...]]

nvmeadm [-dv] identify [-C | -c | -d | [-a] -n] ctl[/ns][,...]

nvmeadm [-dv] identify-controller [-C | -c | [-a] -n] ctl[,...]

nvmeadm [-dv] identify-namespace [-c | -d] ctl/ns[,...]

nvmeadm [-dv] list-logpages [-a] [-H] [-o field[,...] [-p]] [-s scope[,...]] ctl[/ns][,...] [logpage...]

nvmeadm [-dv] get-logpage [-O output-file] ctl[/ns][,...] logpage

nvmeadm [-dv] list-features [-a] [-H] [-o field[,...] [-p]] ctl[/ns][,...] [feature...]

nvmeadm [-dv] get-features ctl[/ns][,...] [feature-list]

nvmeadm [-dv] format ctl[/ns] [lba-format]

nvmeadm [-dv] secure-erase [-c] ctl[/ns]

nvmeadm [-dv] create-namespace -b block-size | -f flbas [-c cap] [-n nmic] [-t type] ctl size

nvmeadm [-dv] delete-namespace ctl/ns

nvmeadm [-dv] attach-namespace ctl/ns

nvmeadm [-dv] detach-namespace ctl/ns

nvmeadm [-dv] attach ctl[/ns]

nvmeadm [-dv] detach ctl[/ns]

nvmeadm [-dv] list-firmware ctl

nvmeadm [-dv] load-firmware ctl firmware-file [offset]

nvmeadm [-dv] commit-firmware ctl slot

nvmeadm [-dv] activate-firmware ctl slot

nvmeadm [-dv] vendor-cmd -O opcode [-n nsid] [--cdw12 cdw12] [--cdw13 cdw13] [--cdw14 cdw14] [--cdw15 cdw15] [-l length [-i file | -o file]] [-L lock] [-I impact[,...]] [-t timeout] ctl[/ns]

nvmeadm [-dv] sandisk/hwrev ctl

nvmeadm [-dv] sandisk/pci-eye -l lane -o output ctl

nvmeadm [-dv] wdc/e6dump -o output ctl

nvmeadm [-dv] wdc/resize -s size | -g ctl

nvmeadm [-dv] wdc/clear-assert ctl

nvmeadm [-dv] wdc/inject-assert ctl

The nvmeadm utility can be used to enumerate the NVMe controllers and their namespaces, query hardware information from a NVMe controller or namespace, and to format or secure-erase a NVMe controller or namespace.

The information returned by the hardware is printed by nvmeadm in a human-readable form were applicable. Generally all 0-based counts are normalized and values may be converted to human-readable units such as MB (megabytes), W (watts), or C (degrees Celsius).

The following options are supported:

Print a short help text for nvmeadm, or for an optionally specified nvmeadm command.
Enable debugging output.
Enable verbose output.

nvmeadm expects the following kinds of arguments:

command
Any command nvmeadm understands. See section COMMANDS.
ctl[/ns]
Specifies a NVMe controller and optionally a namespace within that controller. The controller name consists of the driver name "nvme" followed by an instance number. A namespace is specified by appending a single "/" to the controller name, followed by either the namespace ID or the namespace EUI64 or NGUID as reported by the identify command. The namespace ID is a positive non-zero decimal number. For commands that don't change the device state multiple controllers and namespaces can be specified as a comma-separated list.

The list of controllers and namespaces present in the system can be queried with the list command without any arguments.

logpage
Specifies the log page name for the get-logpage command.
feature-list
A comma-separated list of feature names for the get-features command. Feature names can be specified in upper or lower case. All features can be specified either by a short name listed below or by the full name that the specification uses.
lba-format
A non-zero integer specifying the LBA format for the format command. The list of supported LBA formats on a namespace can be retrieved with the nvmeadm identify command.
firmware-file
Specifies the name of a firmware file to be loaded into the controller using the load-firmware command.
offset
Specifies the byte offset at which to load
output-file
Specifies a file system location to write raw binary data out to. firmware-file within the controller's upload buffer. Vendors may require multiple images to be loaded at different offsets before a firmware set is committed to a slot.
scope
Specifies the scope of a given type of thing to look at, such as a log page. Scopes can either be specified by their full name or a shortened form. For log pages, the following scopes are supported:
Indicates that the log is scoped to the controller. The short form is “ctrl”.
Indicates that the log is scoped to the NVM subsystem. There is no short form.
Indicates that the log is scoped to the namespace. The short form is “ns”.

For more information on the differences between these, please see the NVMe specification.

size
Indicates a size in bytes. The size may be specified in base 10 or in hexadecimal. An optional binary prefix may follow the string. For example, a size of 10G would indicate 10 GiB (Gibibytes) or 10,737,418,240 bytes. Valid binary prefixes include:
The size is in bytes. It is not adjusted.
The size is in KiB. It will be multiplied by 2^10.
The size is in MiB. It will be multiplied by 2^20.
The size is in GiB. It will be multiplied by 2^30.
The size is in TiB. It will be multiplied by 2^40.
The size is in PiB. It will be multiplied by 2^50.

This is used by the create-namespace command.

slot
Specifies the firmware slot into which a firmware set is committed using the commit-firmware command, and subsequently activated with the activate-firmware command. Slots and their contents can be printed using the nvmeadm list-firmware command.

nvmeadm list [-c] [-p -o field[,...]] [ctl[/ns][,...]]
Lists the NVMe controllers and by default also their active namespaces, printing a 1-line summary of their basic properties for each. If a list of controllers and/or namespaces is given then the listing is limited to those devices. If no controllers or namespaces are given as arguments, then all controllers in the system and their respective active namespaces are listed. When using the -v option to nvmeadm, all possible namespaces of the controllers will be listed.

The nvmeadm list command supports the following options:

List controllers only and not their namespaces.
Produce parsable output rather than human-readable output. This option requires that output fields be selected with the -o option.
field[,...]
A comma-separated list of one or more output fields to be used. Fields are listed below and the name is case insensitive.

The following fields can be specified when using the parsable form:

The model number of the device, generally containing information about both the manufacturer and the product.
The NVMe controller's serial number.
The controller's firmware revision.
The version of the NVMe specification the controller supports.
The name of the device node and instance of it.
The /devices path of the controller.

In addition, the following fields can be specified when listing namespaces, not using the -c option:

The amount of logical bytes that the namespace may actually have allocated at any time. This may be different than size due to the use of thin provisioning or due to administrative action.
The logical size in bytes of the namespace.
The number of bytes used in the namespace.
The numerical value of the namespace which can be used as part of other nvmeadm operations.
The name of the disk device that corresponds to the namespace, if any.
The current state of the namespace. This is one of the following:
“unallocated”
the namesapce is currently unallocated. There is no non-volatile memory assosciated with it.
“allocated”
The namespace has non-volatile memory allocated to it, but it is not currently attached to the controller.
“active”
The namespace is currently attached to the local controller; however, the kernel cannot actively attach a block device to the driver.
“active-usable”
The namespace is currently attached to the local controller and the kernel can use the namespace with blkdev(4D).
“blkdev”
The namespace is exposing a block device and is actively attached to blkdev(4D).
The current LBA format of the namespace printed as a string comprised of the data section and the metadata section generally structured as ‘data+meta’. For example, a 4K formatted namespace with no metadata sectors would be shown as ‘4096+0’. A 512-byte formatted namespace with 16 bytes of metadata (perhaps for end-to-end data protection) would be formatted as ‘4096+16’.
The numerical ID of the namespace's LBA format. This may be used as the lba-format argument to the format subcommand.
The data size, in bytes, of the namespace's LBA format.
The metadata size, in bytes, of the namespace's LBA format.

When using the -c option to list controllers, the following additional fields are supported:

The total raw capacity of the NVMe controller in bytes.
The number of bytes not currently assigned to any namespace in the controller.
nvmeadm identify-controller [-C | -c | [-a] -n] ctl[,...]
Print detailed information about the specified controllers. For an explanation of the data printed by this command refer to the description of the "IDENTIFY" admin command in the NVMe specification.

By default, a relevant subset of the "IDENTIFY CONTROLLER" data structure is printed. The full data structure is only printed when verbose output is requested.

The following options can be used to print other "IDENTIFY" information:

Print the Common Namespace Identification of the controller.
Alter the output of the -n option to print the list allocated namespace identifiers. Can only be specified together with the -n option.
Print the list of all unique controller identifiers in the NVMe subsystem the specified controller belongs to.
Print the list of active namespace identifiers of the controller.
nvmeadm identify-namespace [-c | -d] ctl/ns[,...]
Print detailed information about the specified namespace. For an explanation of the data printed by this command refer to the description of the "IDENTIFY" admin command in the NVMe specification.

By default, a relevant subset of the "IDENTIFY NAMESPACE" data structure is printed. The full data structure is only printed when verbose output is requested.

The following options can be used to print other "IDENTIFY" information:

Print the list of all unique controller identifiers in the NVMe subsystem the specified namespace belongs to and which are currently attached to this namespace.
Print the list of namespace identification descriptors of the namespace.
nvmeadm identify [-C | -c | -d | [-a] -n] ctl[/ns][,...]
Short-hand for the identify-controller and identify-namespace commands, prints the same information about the specified controllers and/or namespaces, depending on whether a controller or a namespace was specified.

For a description of the various optional flags refer to the above description of the identify-controller and identify-namespace commands.

nvmeadm [-dv] list-logpages [-a] [-H] [-o field[,...] [-p]] [-s scope[,...]] ctl[/ns][,...] [logpage...]
Prints the list of log pages and information about them specific to the given controller or namespace. This is intended as a discovery mechanism and will print information about mandatory, optional, and vendor-specific log pages as well as all the information that is useful for retrieving information about them.

The nvmeadm list-logpages command supports the following options:

Print all log pages. By default, only logs that are implemented are printed.
Omit the output header columns.
field[,...]
A comma-separated list of one or more output fields to be used. Fields are listed below and the name is case insensitive.
Produce parsable output rather than human-readable output. This option requires that output fields be selected with the -o option.
scope[,...]
Print log pages that match the specified scope. If no scope arguments are specified, then the scope will be set to “ctrl,nvm” when the device is a controller and “ns” when the device refers to a namespace.

The following fields are supported:

Prints the name of the controller or namespace.
Prints the name of the log page. This is the name that can be used to get the log page with the get-logpage command. This is a shortened form from the NVMe or vendor-specific documentation.
This is a description of the log page and generally corresponds to information from the specification the log page is drawn from.
This is the set of scopes that the log page is applicable to. As described earlier in the manual, valid scopes include “ctrl”, “nvm”, and “ns”. This indicates whether a controller (“ctrl” and “nvm”) or a namespace (“ns”) will work for this log page when running the get-logpage command to get the log.
This indicates the command fields that are accepted when retrieving the log page from the controller. The fields include:
Indicates that a log specific parameter is accepted for this page.
Indicates that a log specific identifier is accepted for this page.
Indicates that one can control whether or not an asynchronous event is retained when retrieving the log page. By default, asynchronous events are cleared when certain log pages are fetched such as the health log page.
For more information on these fields, please see the NVMe specification.
Indicates the log page's command set interface.
Indicates the log page's numeric ID. This when combined with the log page's CSI is the unique identifier that identifies the log page to the controller.
Indicates whether or not the system believes that the log page is implemented.
Indicates the size of the log page. Not all log pages have a fixed size and in such cases this field will not contain a value.
When a log page is known to have a variable size, this indicates the minimum amount of the log page to read to determine the full size of the log page.
This is a comma separated list of values that indicates where information about this log page and its support came from primarily. These include the following:
“spec”
This comes from the NVMe specification. Generally this refers to mandatory log pages that are not dependent on any information in the identify controller data structure.
“identify-controller”
Information about this log page comes from the identify controller data structure. Many log pages are described by the standard but are optional and their support is indicated through that.
“internal-db”
This indicates that information about this log page comes from our internal databases in libnvme. Most vendor-specific logs are described in datasheets whose information is encoded into the library and system and there is not always a way to discover that it is supported or not.
“command”
This indicates that information about this log page came from another command that was issued to the controller which indicates what was implemented and present.
This indicates the kind of log page that this is. Valid options are:
“mandatory”
Indicates that the NVMe specification considers this mandatory for all controllers of a given version.
“optional”
Indicates that the NVMe specification considers this log page optional. Some items may be mandatory if a device implements an optional feature like namespace management, but they will still be considered optional as the underlying feature is.
“vendor-specific”
Indicates that this log is a vendor-specific log page. These log pages are not part of the NVMe standard and are generally described in their own device's datasheets or a separate standard such as the OCP Datacenter NVMe SSD Specification.

The list-logpages command supports a series of operands which can be used to filter the list of log pages that information is printed out about. Each logpage operand is the name of a log page. Only matching log pages will be printed and if no log pages match a given operand argument or not log pages are printed at all (which can happen due to a log being unsupported) then the command will generate an error.

nvmeadm get-logpage [-O output-file] ctl[/ns][,...] logpage
Print the specified log page of the specified controllers and/or namespaces. If -O is specified, rather than print the contents of the log, the raw binary payload of the log will be written to output-file. Most log pages are only available on a per-controller basis. Known log pages are:
suplog
Supported Log Pages. Lists information about log pages that the device supports. Available starting in NVMe 2.0 devices.
error
Error Information
health
SMART/Health Information. A controller may support this log page on a per-namespace basis.
firmware
Firmware Slot Information
changens
Changed Namespaces.
cmdeff
Commands Supported and Effects. An optional log page added in NVMe 1.2 that indicates what commands the controller itself actually supports.
pev
Persistent Event Log. An optional log page added in NVMe 1.4 that contains a series of events that have occurred on the device.
telemetry
Host-initiated telemetry log. Contains vendor-specific diagnostic information about the controller. This log page requires that the -O option be specified.

The following vendor-specific log pages are supported. Not all devices from a vendor support every log page. Use the list-logpages command to determine which are supported for a given device and whether they operate on a controller or namespace.

kioxia/extsmart
Kioxia Extended SMART.
micron/smart
Micron Vendor Unique SMART.
micron/extsmart
Micron Extended SMART.
ocp/smart
Open Compute Datacenter NVMe SSD specification SMART / Health information.
ocp/errrec
Open Compute Datacenter NVMe SSD specification error recovery log.
ocp/fwact
Open Compute Datacenter NVMe SSD specification firmware activation log.
ocp/latency
Open Compute Datacenter NVMe SSD specification latency monitor.
ocp/devcap
Open Compute Datacenter NVMe SSD specification device capabilities.
ocp/unsup
Open Compute Datacenter NVMe SSD specification unsupported requirements.
solidigm/rlat
Solidigm/Intel read command latency statistics.
solidigm/wlat
Solidigm/Intel write command latency statistics.
solidigm/temp
Solidigm/Intel temperature statistics.
solidigm/smart
Solidigm/Intel vendor unique SMART log.
solidigm/ioqueue
Solidigm/Intel I/O queue metrics.
solidigm/name
Solidigm/Intel drive marketing name.
solidigm/power
Solidigm/Intel power usage.
solidigm/gc
Solidigm/Intel garbage collection.
solidigm/outlier
Solidigm/Intel latency outlier.
wdc/eol
Western Digital end-of-life.
wdc/devmgmt
Western Digital device manageability.
wdc/pciesi
Western Digital PCIe signal integrity.
wdc/power
Western Digital power samples.
wdc/temp
Western Digital temperature samples.
wdc/fwact
Western Digital firmware activation history.
wdc/ccds
Western Digital CCDS build information.
wdc/cusmart
Western Digital customer unique SMART data.

For an explanation of the contents of the log pages refer to the description of the "GET LOGPAGE" admin command in the NVMe specification.

nvmeadm list-features [-a] [-H] [-o field[,...] [-p]] ctl[/ns][,...] [feature[,...]]
Prints the list of features and information about them specific to the given controller or namespace. This is intended as a discovery mechanism and will print information about known mandatory, optional, and vendor-specific features as well as the information that is useful for retrieving information about them.

The nvmeadm list-features command supports the following options:

Print all features, regardless of whether or not the controller is known to implement them. By default unimplemented features are not printed, but implemented and unknown ones are.
Omit the output header columns.
field[,...]
A comma-separated list of one or more output fields to be used. Fields are listed below and the name is case insensitive.
Produce parsable output rather than human-readable output. This option requires that output fields be selected with the -o option.

The following fields are supported:

Prints the name of the controller or namespace.
This is a shortened name for a feature which can be used to identify it. These short names are unique to illumos and not part of the NVMe specification.
This is the specification's name for a given feature.
This is the numeric ID that can be used to uniquely identify a feature.
This is a comma separated list of values that identifies what scopes this feature covers. The supported scopes are “controller”, which indicates that it impacts the entire controller and “namespace”, which indicates that it impacts just a single namespace.
This indicates the kind of feature that this is. Valid options are:
“mandatory”
Indicates that the NVMe specification considers this mandatory for all controllers of a given version.
“optional”
Indicates that the NVMe specification considers this feature optional. Some items may be mandatory if a device implements an optional feature like namespace management, but they will still be considered optional as the underlying feature is.
“vendor-specific”
Indicates that this log is a vendor-specific feature. These features are not part of the NVMe standard and are generally described in their own device's datasheets or a separate standard such as the OCP Datacenter NVMe SSD Specification.
The command set interface that the feature is specific to. Most features are not specific to a CSI.
The flags are a series of comma separated strings which describe properties of the feature. The following flags are currently supported:
“get-bcastns”
Indicates that the broadcast namespace is supported when getting this feature.
“set-bcastns”
Indicates that the broadcast namespace is supported when setting this feature. Using the broadcast namespace indicates that all namespace are impacted.
A series of comma separated values indicating what is required to get this feature. The following values are supported:
cdw11
Indicates that the feature requires an argument in the cdw11 field of the command. This is generally a selector of some kind. For example, for the temperature threshold feature, it selects which of several sensors may be referred to.
data
Indicates that a data buffer is required when getting this feature. Its size is indicated by the DATALEN field.
nsid
Indicates that a namespace ID is required when getting this feature.
A series of comma separated values indicating what is required to get this feature. The following values are supported:
cdw11
Indicates that the feature uses information in cdw11 to set the feature.
cdw12
Indicates that the feature uses information in cdw12 to set the feature.
cdw13
Indicates that the feature uses information in cdw13 to set the feature.
cdw14
Indicates that the feature uses information in cdw14 to set the feature.
cdw15
Indicates that the feature uses information in cdw15 to set the feature.
data
Indicates that the feature takes a data payload to set the feature. Its size is indicated by the DATALEN field.
nsid
Indicates that the feature requires a valid namespace identifier.
A series of comma separated values indicating what the controller will return information about this feature in. The following values are supported:
cdw0
Indicates that the controller will give information about the feature in the command output 32-bit value.
data
Indicates that the controller will output information about the feature into the output buffer.
A series of comma separated values indicating what the controller will update following the successful completion of setting the feature. These values are the same as with the GET-OUT field.
Indicates the length of data for the feature.
Indicates whether or not the feature is known to be implemented or not. The following values are possible:
“unknown”
Indicates that it is unknown as to whether or not the feature is implemented. Some features are optional and there is no way to determine this short of issuing an attempt to get the feature itself.
“yes”
Indicates that we know the feature is implemented by the controller.
“no”
Indicates that we know the feature is not implemented by the controller.

The list-features command supports a series of operands which can be used to filter the list of features that information is printed out about. Each feature operand is either the short name or the specification's name for a given feature. In addition, the numeric feature ID can also be used as a filter. If no features match a given operand or no features are printed at all then the command will generate an error.

nvmeadm get-features ctl[/ns][,...] [feature-list]
Prints information about the specified features, or all features if none are given, of the specified controllers and/or namespaces. Feature names are case-insensitive, and they can be shortened as long as they remain unique. Some features also have alternative short names to which the same rules apply. The following features are supported:

FULL NAME SHORT NAME CONTROLLER/NAMESPACE
Arbitration arb controller
Power Management pm controller
LBA Range Type range namespace
Temperature Threshold temp controller
Error Recovery errec controller
Volatile Write Cache cache controller
Number of Queues queues controller
Interrupt Coalescing coalescing controller
Interrupt Vector Configuration vector controller
Write Atomicity atomicity controller
Asynchronous Event Configuration event controller
Autonomous Power State Transition apst controller
Software Progress Marker progress controller
Host Behavior Support hostsup controller

For an explanation of the individual features refer to the description of the "SET FEATURES" admin command in the NVMe specification.

nvmeadm format ctl[/ns] [lba-format]
Formats the specified namespace or all namespaces of the specified controller. This command implies a nvmeadm detach and subsequent nvmeadm attach of the specified namespace(s), which will cause a changed LBA format to be detected. If no LBA format is specified the LBA format currently used by the namespace will be used. When formatting all namespaces without specifying a LBA format the LBA format of namespace 1 will be used. A list of LBA formats supported by a namespace can be queried with the nvmeadm identify command.

Note that not all devices support formatting individual or all namespaces, or support formatting at all.

LBA formats using a non-zero metadata size are not supported by nvmeadm or nvme(4D).

The list of supported LBA formats on a namespace can be retrieved with the nvmeadm identify command.

nvmeadm secure-erase [-c] ctl[/ns]
Erases the specified namespace or all namespaces of the controller. The flag -c will cause a cryptographic erase instead of a normal erase. This command implies a nvmeadm detach and nvmeadm attach of the specified namespace(s).

Note that not all devices support erasing individual or all namespaces, or support erasing at all.

nvmeadm create-namespace -b block-size | flbas [-c cap] [-n nmic] [-t type] ctl size
Creates a new namespace of size size in the controller ctl. NVM will be allocated for the namespace and the namespace will transition to the allocated state. A created namespace must subsequently be attached to the local controller, attach-namespace, and to the block device framework (blkdev(4D)), attach, to provide I/O capabilities.

By default, a newly created namespace:

  • Uses the NVM command set interface (CSI). This can be changed with the -t option.
  • Has the namespace's capacity set to the namespace's size. To thinly provision a namespace, you may use the -c option to specify a value less than the size argument. Note, the controller may not support thin provisioning.
  • Configures the namespace so it may only be used with one controller at a time. This can be changed with the -n option.

When creating a namespace, one must specify what formatted LBA index to use. This index may be specified directly with the -f option or instead the target block size may be specified with the -b option. If -b is specified, then the command will search for a namespace with that block size, with no metdata section, and with the highest relative performance and use that. Available LBA format options may be listed by printing the Common Namespace Identification values through the identify-controller option with the -C option.

The create-namespace command supports the following options:

block-size
Specifies the target data block size of the namespace to be created. This option is exclusive with the -f option. block-size allow a binary prefix to be specified as per the description of the size operand.
cap
Specifies the namespace's capacity in bytes, which may use a binary prefix like, such as 100G, as per the description of the size operand. If this option is left out, the namespace's capacity will be set to its size, fully provisioning the namespace. Not all controllers support thinly provisioning a namespace.
flbas
Specifies the index of the formatted LBA size.
nmic
Specifies the multipath I/O and namespace sharing capabilities. The current valid options for this are:
Indicates that only a single controller may attach to the namespace at any given time.
Indicates that two or more controllers may attach to the namespace at the same time.
type
Specifies the command set interface for newly created namespace. The default is “nvm”. The system understands the following command set interfaces; however, not all controllers support all CSIs and currently the nvme(4D) driver only supports the NVM CSI.
nvm
The non-volatile memory CSI. This is the default CSI of all NVMe devices and provides a regular block interface.
kv
Key Value command set interface. This interface does not provide standard a logical block abstraction and instead allows for someone to read and write an arbitrary-sized object with a 128-bit key.
zns
Zoned namespace command set interface. This interface provides a block-like abstraction where blocks are broken into different sized zones, which contain ranges of logical blocks. Writing to a zone offers different semantics from a common block device.
nvmeadm delete-namespace ctl/ns
This deletes the specified namespace, freeing any capacity back to the underlying NVM subsystem. The namespace identifier will be considered inactive in ctl.

To delete a namespace, the namespace must already be detached from all controllers through the detach-namespace command.

Upon deleting a namespace, all information that was contained in the namespace .

nvmeadm attach-namespace ctl/ns
Attach the specified namespace to the controller ctl. This will transition the namespace to the active state, allowing additional information about the namespace to be queried. This also allows the namespace to provide a block device interface through blkdev(4D), which can be enabled by subsequently using the attach command.
nvmeadm detach-namespace ctl/ns
Detach the specified namespace from the controller ctl. The namespace must already be detached from blkdev(4D) through the detach command. When detached, the namespace transitions from active to allocated in the controller. Data in the namespace remains valid; however, not all commands will function against the namespace and I/O may not be performed to it.
nvmeadm attach ctl[/ns]
Attaches the blkdev(4D) instance to the specified namespace or all namespaces of the controller. This will make I/O accesses to the namespace(s) possible again after a previous nvmeadm detach command.

It is not an error to attach a namespace that is already attached, any such request will be silently ignored.

nvmeadm detach ctl[/ns]
Temporarily detaches the blkdev(4D) instance from the specified namespace or all namespaces of the controller. This will prevent I/O access to the affected namespace(s). Detach will only succeed if the affected namespace(s) are not currently opened. The detached state will not persist across reboots or reloads of the nvme(4D) driver.

It is not an error to detach a namespace that is already detached, any such request will be silently ignored.

nvmeadm list-firmware ctl
List currently active firmware slot, the next active firmware slot, and the current contents of all firmware slots of an NVMe controller. This is a synonym for the nvmeadm get-logpage ctl firmware command.
nvmeadm load-firmware ctl firmware-file [offset]
Loads firmware-file into the controller's upload memory at offset, the default is 0. A vendor may require multiple files to be loaded at different offsets before the firmware is committed to a slot.
nvmeadm commit-firmware ctl slot
Commits firmware previously loaded by the load-firmware command to slot.
nvmeadm activate-firmware ctl slot
Activates the firmware in slot slot. The firmware image in slot is activated at the next NVM controller reset.
nvmeadm vendor-cmd -O opcode [-n nsid] [--cdw12 cdw12] [--cdw13 cdw13] [--cdw14 cdw14] [--cdw15 cdw15] [-l length [-i file | -o file]] [-L lock] [-I impact[,...]] [-t timeout] ctl[/ns]
This allows an administrator to send a vendor-specific command to a device that supports the NVMe standard vendor specific command format. Vendor-specific commands must be used carefully. While the system attempts to first class many commands so that way we can ensure that anything that causes confusion to the device is well understood, this cannot be done for arbitrary commands. It is the user's responsibility to understand if this can cause the controller to lose data, interact poorly with the kernel leading to the driver being out of sync with reality, or worse. The only required argument for this is an operation code which must be in the vendor-specific region.

The command may be run against either a controller or a namespace. When a namespace is specified, its namespace id is included in the command.

A command may optionally request that data be sent to the controller as an input to the command (-i), or returned by the controller as an output from the command (-o). There is no support in the standard protocol for both an arbitrary sized data input and output. The length of the input is specified by the -l flag, which indicates a size in bytes that must be a multiple of 4 (commands operate in units of uint32_t). Data is either read from or output to a file. The maximum input or output data size provided by the system is 16 MiB.

When the command completes, it will print out the results of the command and the value of the completion command dword 0.

The following arguments are supported:

, --opcode opcode
Sets the numeric operation code that should be used for the command. This option is required. Valid values are in the range [0xc0, 0xff].
, ---nsid nsid
Sets the namespace identifier to send in the command to nsid. If the command is specified against a namespace specifically, then this argument is not required. If the nsid argument is specified and a namespace is specified as the target, they must agree otherwise it is an error.

If no namespace ID is specified, this field will be set to 0 in the command.

, -2 cdw12
Sets the 32-bit value of command dword 12 to the value cdw12. Whether or not this is required is command specific.

If no value is specified, this field will be set to 0 in the command.

, -3 cdw13
Sets the 32-bit value of command dword 13 to the value cdw13. Whether or not this is required is command specific.

If no value is specified, this field will be set to 0 in the command.

, -4 cdw14
Sets the 32-bit value of command dword 14 to the value cdw14. Whether or not this is required is command specific.

If no value is specified, this field will be set to 0 in the command.

, -5 cdw15
Sets the 32-bit value of command dword 15 to the value cdw15. Whether or not this is required is command specific.

If no value is specified, this field will be set to 0 in the command.

, --length length
Indicates the length in bytes of the desired input or output for the command. The length must be 4-byte aligned. If this is specified, one of -i or -o must be specified to indicate the direction of the data transfer and the source or destination of the data.
, --input file
Read the input to the command from file. Requires that -l is specified. If the input file, file, is shorter than the length specified with -l, then the remaining data will be filled with 0s.
, --output file
Write controller output to file. Requires that -l is specified.
, ---lock lock
Allows for a read or write lock on the controller (or namespace) to be taken for the duration of the command. The following values are supported for lock:
Takes a read lock on the controller Pq or namespace . I/O will still continue during this time. This prevents other operations from modifying the state of the controller or namespace such as performing a format, firmware update, etc.
Takes an exclusive write lock on the controller. I/O will still continue during this; however, no other administrative actions will be allowed during this time including read-only commands.
, --impact impact[,...]
A comma-separated list of values that describe to the system the impact of running this command on the system. By default, no impact to the system is assumed. The following values are accepted:
Indicates that the data on the controller or namespace may be lost as a result of running this command.
Indicates that namespaces and their attributes may be modified as a result of running this command.
, --timeout timeout
All administrative commands are monitored by the system to ensure that they complete in a timely fashion. By default a 60 second timeout is applied to all administrative commands. This may be overridden by specifying a new timeout value which will be interpreted in seconds.
nvmeadm sandisk/hwrev ctl
This vendor-specific command prints the device hardware revision.
nvmeadm sandisk/pci-eye -l lane -o output ctl
This vendor-specific command obtains a PCIe eye diagram for the hardware lane specified by lane on the NVMe device ctl. The PCIe lane will generally be between 0 and 3, though it is possible fewer lanes will be available depending on the drive bay and system board design. The information will be output to the file output.
nvmeadm wdc/e6dump -o output ctl
This vendor-specific command performs a diagnostic dump of device data to the file specified by output. The device remains in full service while this is occurring.
nvmeadm wdc/resize -s size | ctl
This vendor-specific command will get the current over provisioning size or set it. This command operates using power of 10 bytes, that is in terms of gigabytes and not gibibytes. The sizes that are used here will be different from those that the operating system will report for the drive.

The following options are supported:

Returns the current size of the device in gigabytes (powers of 10).
size
Sets the size of the device to size which is in gigabytes (powers of 10). This can be used to adjust the over provisioning ratio on the device. The valid points are device-specific. Please consult WDC datasheets for more information.

When performing a resize ! All namespaces must be detached prior to issuing this.

nvmeadm [-dv] wdc/clear-assert ctl
This clears an internal assertion record from a WDC device. Prior to running this any such internal assertion should be saved by using the wdc/e6dump command. This command should only be used if instructed to do so as part of a troubleshooting process.
nvmeadm [-dv] wdc/inject-assert ctl
This injects a device assertion into a WDC NVMe device. The behavior of doing so is device specific; however, all I/O will be interrupted and the device may be retired. Unless explicitly instructed as part of debugging a device or as part of internal development, this command should not be used.

The nvmeadm utility exits 0 on success, and >0 if an error occurs.

# nvmeadm list
nvme1: model: INTEL SSDPEDMD800G4, serial: CVFT4134001R800CGN, FW rev: 8DV10049, NVMe v1.0
  nvme1/1 (c1t1d0): Size = 763097 MB, Capacity = 763097 MB, Used = 763097 MB
nvme4: model: SAMSUNG MZVPV128HDGM-00000, serial: S1XVNYAGA00640, FW rev: BXW7300Q, NVMe v1.1
  nvme4/1 (c2t2d0): Size = 122104 MB, Capacity = 122104 MB, Used = 5127 MB
# nvmeadm identify nvme4/1
nvme4/1: Identify Namespace
  Namespace Capabilities and Features
    Namespace Size:                         122104MB
    Namespace Capacity:                     122104MB
    Namespace Utilization:                  5127MB
    Namespace Features
      Thin Provisioning:                    unsupported
    Number of LBA Formats:                  1
    Formatted LBA Size
      LBA Format:                           1
      Extended Data LBA:                    no
    Metadata Capabilities
      Extended Data LBA:                    unsupported
      Separate Metadata:                    unsupported
    End-to-End Data Protection Capabilities
      Protection Information Type 1:        unsupported
      Protection Information Type 2:        unsupported
      Protection Information Type 3:        unsupported
      Protection Information first:         unsupported
      Protection Information last:          unsupported
    End-to-End Data Protection Settings
      Protection Information:               disabled
      Protection Information in Metadata:   last 8 bytes
    LBA Format 1
      Metadata Size:                        0 bytes
      LBA Data Size:                        512 bytes
      Relative Performance:                 Best
# nvmeadm -v get-logpage nvme4/1 health
nvme4/1: SMART/Health Information
  Critical Warnings
    Available Space:                        OK
    Temperature:                            OK
    Device Reliability:                     OK
    Media:                                  OK
    Volatile Memory Backup:                 OK
  Temperature:                              37C
  Available Spare Capacity:                 100%
  Available Spare Threshold:                10%
  Device Life Used:                         0%
  Data Read:                                0GB
  Data Written:                             64GB
  Read Commands:                            52907
  Write Commands:                           567874
  Controller Busy:                          1min
  Power Cycles:                             6
  Power On:                                 141h
  Unsafe Shutdowns:                         1
  Uncorrectable Media Errors:               0
  Errors Logged:                            1
# nvmeadm get-features nvme0,nvme4 event,power
nvme0: Get Features
  Asynchronous Event Configuration
    Available Space below threshold:        disabled
    Temperature above threshold:            disabled
    Device Reliability compromised:         disabled
    Media read-only:                        disabled
  Power Management
    Power State:                            0
nvme4: Get Features
  Asynchronous Event Configuration
    Available Space below threshold:        disabled
    Temperature above threshold:            disabled
    Device Reliability compromised:         disabled
    Media read-only:                        disabled
    Volatile Memory Backup failed:          disabled
  Power Management
    Power State:                            0
# nvmeadm list-firmware nvme3
nvme3: Firmware Slot Information
  Active Firmware Slot:                     4
  Next Firmware Slot:                       4
  Firmware Revision for Slot 1:             KNGND110 (read-only)
  Firmware Revision for Slot 2:             KNGND110
  Firmware Revision for Slot 3:             KNGND110
  Firmware Revision for Slot 4:             KNGND112
  Firmware Revision for Slot 5:             KNGND110

# nvmeadm -v load-firmware nvme3 KNGND113.bin
1740544 bytes downloaded.

# nvmeadm -v commit-firmware nvme3 5
Firmware committed to slot 5.

# nvmeadm -v activate-firmware nvme3 5
Slot 5 activated: NVM subsystem reset required - power cycle your system.

# nvmeadm list-firmware nvme3
nvme3: Firmware Slot Information
  Active Firmware Slot:                     4
  Next Firmware Slot:                       5
  Firmware Revision for Slot 1:             KNGND110 (read-only)
  Firmware Revision for Slot 2:             KNGND110
  Firmware Revision for Slot 3:             KNGND110
  Firmware Revision for Slot 4:             KNGND112
  Firmware Revision for Slot 5:             KNGND113
# nvmeadm list-logpages nvme8
DEVICE  NAME          SCOPE         FIELDS    DESC
nvme8   error         controller    rae       Error information
nvme8   health        controller,   rae       SMART / Health information
                      namespace
nvme8   firmware      nvm           --        Firmware Slot Information
nvme8   changens      controller    rae       changed namespaces
nvme8   wdc/eol       nvm           --        EOL
nvme8   wdc/devmgmt   controller,   --        Device Manageability
                      namespace
nvme8   wdc/pciesi    controller    lsp       PCIe Signal Integrity
nvme8   wdc/power     controller    --        Power Samples
nvme8   wdc/temp      controller    --        Temperature Samples
nvme8   wdc/fwact     controller    --        Firmware Activation
nvme8   wdc/ccds      controller    --        CCDS Build Information
# nvmeadm list-logpages -p -o name,impl nvme8 firmware
firmware:yes

The command line interface of nvmeadm is . The output of nvmeadm is and may change any time.

nvme(4D)

NVMe specifications

January 30, 2026 OmniOS