nvme-id-ctrl man page

nvme-id-ctrl — Send NVMe Identify Controller, return result and structure

Synopsis

nvme id-ctrl <device> [-v | --vendor-specific] [-b | --raw-binary]
                        [-o <fmt> | --output-format=<fmt>]

Description

For the NVMe device given, sends an identify controller command and provides the result 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

-b, --raw-binary
Print the raw buffer to stdout. Structure is not parsed by program. This overrides the vendor specific and human readable options.
-v, --vendor-specific
In addition to parsing known fields, this option will dump the vendor specific region of the structure in hex with ascii interpretation.
-H, --human-readable
This option will parse and format many of the bit fields into human-readable formats.
-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-ctrl /dev/nvme0

· In addition to showing the known fields, has the program to display the vendor unique field:

# nvme id-ctrl /dev/nvme0 --vendor-specific
# nvme id-ctrl /dev/nvme0 -v

The above will dump the vs buffer in hex since it doesn’t know how to interpret it.

· Have the program return the raw structure in binary:

# nvme id-ctrl /dev/nvme0 --raw-binary > id_ctrl.raw
# nvme id-ctrl /dev/nvme0 -b > id_ctrl.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-ctrl /dev/nvme0 --raw-binary | nvme_parse_id_ctrl

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_ctrl.c */

#include <linux/nvme.h>
#include <stdio.h>
#include <unistd.h>

int main(int argc, char **argv)
{
        unsigned char buf[sizeof(struct nvme_id_ctrl)];
        struct nvme_id_ctrl *ctrl = (struct nvme_id_ctrl *)buf;

        if (read(STDIN_FILENO, buf, sizeof(buf)))
                return 1;

        printf("vid   : %#x\n", ctrl->vid);
        printf("ssvid : %#x\n", ctrl->ssvid);
        return 0;
}

Nvme

Part of the nvme-user suite

Referenced By

nvme(1).

10/21/2016 NVMe NVMe Manual