nvme-get-feature.1

NVME−GET−FEATURE

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLES
NVME

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NAME

nvme-get-feature − Gets an NVMe feature, returns applicable results

SYNOPSIS

nvme get−feature <device> [−−namespace−id=<nsid> | −n <nsid>]
[−−feature−id=<fid> | −f <fid>]
[−−uuid−index=<uuid−index> | −U <uuid_index>]
[−−data−len=<data−len> | −l <data−len>]
[−−sel=<select> | −s <select>]
[−−raw−binary | −b] [−−cdw11=<cdw11> | −c <cdw11>]
[−−human−readable | −H] [−−changed | −C]
[−−output−format=<fmt> | −o <fmt>] [−−verbose | −v]
[−−timeout=<timeout> | −t <timeout>]

DESCRIPTION

Submits an NVMe Get Feature admin command and returns the applicable results. This may be the feature’s value, or may also include a feature structure if the feature requires it (ex: LBA Range Type).

The <device> parameter is mandatory and may be either the NVMe character device (ex: /dev/nvme0), or a namespace block device (ex: /dev/nvme0n1).

On success, the returned feature’s structure (if applicable) may be returned in one of several ways depending on the option flags; the structure may parsed by the program and printed in a readable format if it is a known structure, displayed in hex, or the raw buffer may be printed to stdout for another program to parse.

OPTIONS

−n <nsid>, −−namespace−id=<nsid>

Retrieve the feature for the given nsid. This is optional and most features do not use this value.

−f <fid>, −−feature−id=<fid>

The feature id to send with the command. Value provided should be in hex.

−s <select>, −−sel=<select>

Select (SEL): This field specifies which value of the attributes to return in the provided data:

−U <uuid−index>, −−uuid−index=<uuid−index>

UUID Index of the feature

−l <data−len>, −−data−len=<data−len>

The data length for the buffer returned for this feature. Most known features do not use this value. The exception is LBA Range Type

−c <cdw11>, −−cdw11=<cdw11>

The value for command dword 11, if applicable.

−b, −−raw−binary

Print the raw feature buffer to stdout if the feature returns a structure.

−H, −−human−readable

This option will parse and format many of the bit fields into human−readable formats.

−C, −−changed

This option will show feature changed.

−o <fmt>, −−output−format=<fmt>

Set the reporting format to normal, json or binary. Only one output format can be used at a time.

−v, −−verbose

Increase the information detail in the output.

−t <timeout>, −−timeout=<timeout>

Override default timeout value. In milliseconds.

EXAMPLES

• Retrieves the feature for Number of Queues, or feature id 7:

nvme get−feature /dev/nvme0 −f 7

• The following retrieves the feature for the LBA Range Type, which implicitly requires a buffer and will be printed to the screen in human readable format:

nvme get−feature /dev/nvme0 −f 3

• Retrieves the feature for the some vendor specific feature and specifically requesting a buffer be allocate for this feature, which will be displayed to the user in as a hex dump:

nvme get−feature /dev/nvme0 −f 0xc0 −l 512

Get feature with UUID index

nvme get−feature /dev/nvme0 −f 0xc0 −l 512 −U 0x1

• The following retrieves the feature for the LBA Range Type, which implicitly requires a buffer and will be saved to a file in its raw format:

nvme get−feature /dev/nvme0 −f 3 −−raw−binary > lba_range.raw

It is probably a bad idea to not redirect stdout when using this mode.

NVME

Part of the nvme−user suite

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