SYNOPSIS

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