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Diffstat (limited to 'Documentation/nvme-id-ns-lba-format.txt')
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diff --git a/Documentation/nvme-id-ns-lba-format.txt b/Documentation/nvme-id-ns-lba-format.txt new file mode 100644 index 0000000..32df2f6 --- /dev/null +++ b/Documentation/nvme-id-ns-lba-format.txt @@ -0,0 +1,102 @@ +nvme-id-ns-lba-format(1) +======================== + +NAME +---- +nvme-id-ns-lba-format - Send NVMe Identify Namespace for the specified LBA Format index, display structure + +SYNOPSIS +-------- +[verse] +'nvme id-ns' <device> [--uuid-index=<uuid-index> | -U <uuid_index>] + [--lba-format-index=<lba_format_index> | -i <lba_format_index>] + [-v | --verbose] + [--output-format=<fmt> | -o <fmt>] + +DESCRIPTION +----------- +For the NVMe device given, sends an identify namespace for +the specified LBA Format index command and provides the result +that is include capability field only and returned structure. + +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 structure may be returned in one of several ways depending +on the option flags; the structure may be parsed by the program or the +raw buffer may be printed to stdout. + +OPTIONS +------- +-U <uuid-index>:: +--uuid-index=<uuid-index>:: + UUID Index of the feature + +-i <lba_format_index>:: +--lba-format-index=<lba_format_index>:: + This field specifies the index into the LBA Format list identifying + the LBA Format capabilities that are to be returned + +-v:: +--verbose:: + Increase the information detail in the output. + +-o <format>:: +--output-format=<format>:: + Set the reporting format to 'normal', 'json', or + 'binary'. Only one output format can be used at a time. + +EXAMPLES +-------- +* Has the program interpret the returned buffer and display the known +fields in a human readable format: ++ +------------ +# nvme id-ns-lba-format /dev/nvme0n1 -i 0 +------------ ++ +* Have the program return the raw structure in binary: ++ +------------ +# nvme id-ns-lba-format /dev/nvme0n1 -i 0 -o binary > id_ns.raw +# nvme id-ns-lba-format /dev/nvme0n1 -i 0 --output-format=binary > id_ns.raw +------------ ++ +It is probably a bad idea to not redirect stdout when using this mode. + +* Alternatively you may want to send the data to another program that +can parse the raw buffer. ++ +------------ +# nvme id-ns-lba-format /dev/nvme0n1 -i 0 --raw-binary | nvme_parse_id_ns +------------ ++ +The parse program in the above example can be a program that shows the +structure in a way you like. The following program is such an example +that will parse it and can accept the output through a pipe, `'|'`, +as shown in the above example, or you can `'cat'` a saved output buffer +to it. +------------ +/* File: nvme_parse_id_ns_lba_format.c */ + +#include <linux/nvme.h> +#include <stdio.h> +#include <unistd.h> + +int main(int argc, char **argv) +{ + unsigned char buf[sizeof(struct nvme_id_ns)]; + struct nvme_id_ns *ns = (struct nvme_id_ns *)buf; + + if (read(STDIN_FILENO, buf, sizeof(buf))) + return 1; + + printf("nsze : %#llx\n", ns->nlbaf); + printf("ncap : %#llx\n", ns->mc); + return 0; +} +------------ + +NVME +---- +Part of the nvme-user suite |