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>] [--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]

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:

           ┌───────┬────────────────────────┐
           │Select │ Description            │
           ├───────┼────────────────────────┤
           │0      │ Current                │
           ├───────┼────────────────────────┤
           │1      │ Default                │
           ├───────┼────────────────────────┤
           │2      │ Saved                  │
           ├───────┼────────────────────────┤
           │3      │ Supported capabilities │
           ├───────┼────────────────────────┤
           │4-7    │ Reserved               │
           └───────┴────────────────────────┘

       -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.

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