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