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



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


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


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.


−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.


• 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;


Part of the nvme−user suite

Updated 2024-01-29 - jenkler.se | uex.se