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>] [--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] [--output-format=<fmt> | -o <fmt>] [--verbose | -v] 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 -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. -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. 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