nvme-id-ctrl(1)

SYNOPSIS

nvme [<global-options>] id-ctrl <device>
                        [--vendor-specific | -V]
                        [--raw-binary | -b]
                        [--human-readable | -H]

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: Display values in a human-readable format where possible. (deprecated, use --verbose)

GLOBAL OPTIONS

The following options are defined at the top-level nvme command and are available to this subcommand:

--dry-run: Print the command that would be executed, but do not actually execute it.
--no-ioctl-probing: Disable probing for 64-bit IOCTL support.
--no-retries: Disable retry logic on transient errors.
-o <fmt>
--output-format=<fmt>: Set the reporting format to normal, tabular, 'json, or binary. Only one output format may be used at a time.
--output-format-version=<version>: Select the output format version. Version 1 uses the original field naming, while version 2 (default) provides more consistent and script-friendly field names.
--timeout=<ms>: Set the timeout for the command in milliseconds.
-v
--verbose: Increase the level of detail in the output. May be specified multiple times to further increase verbosity.

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