nvme-get-feature − Gets an NVMe feature, returns applicable results
nvme
get−feature <device>
[−−namespace−id=<nsid> | −n
<nsid>]
[−−feature−id=<fid> | −f
<fid>] [−−cdw11=<cdw11>]
[−−uuid−index=<uuid−index> |
−U <uuid_index>]
[−−data−len=<data−len> |
−l <data−len>]
[−−sel=<select> | −s <select>]
[−−raw−binary | −b]
[−−human−readable | −H]
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.
−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
−−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.
• 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.
Part of the nvme−user suite