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Diffstat (limited to 'Documentation/nvme-get-feature.txt')
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diff --git a/Documentation/nvme-get-feature.txt b/Documentation/nvme-get-feature.txt new file mode 100644 index 0000000..56542dc --- /dev/null +++ b/Documentation/nvme-get-feature.txt @@ -0,0 +1,118 @@ +nvme-get-feature(1) +=================== + +NAME +---- +nvme-get-feature - Gets an NVMe feature, returns applicable results + +SYNOPSIS +-------- +[verse] +'nvme get-feature' <device> [--namespace-id=<nsid> | -n <nsid>] + [--feature-id=<fid> | -f <fid>] [--cdw11=<cdw11>] + [--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 +|================== + +-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 +------------ ++ + +* 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 |