nvme-id-ns - Online in the Cloud

PROGRAM:

NAME

nvme-id-ns - Send NVMe Identify Namespace, return result and structure

SYNOPSIS

nvme id-ns <device> [-v | --vendor-specific] [-b | --raw-binary]
[--namespace-id=<nsid> | -n <nsid>]

DESCRIPTION

For the NVMe device given, sends an identify namespace 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). If the character device is
given, the '--namespace-id' option is mandatory, otherwise it will use the ns-id of the
namespace for the block device you opened. For block devices, the ns-id used can be
overridden with the same option.

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

-n <nsid>, --namespace-id=<nsid>
Retrieve the identify namespace structure for the given nsid. This is required for the
character devices, or overrides the block nsid if given.

-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.

EXAMPLES

· Has the program interpret the returned buffer and display the known fields in a human
readable format:

# nvme id-ns /dev/nvme0n1

· If using the character device or overriding namespace id:

# nvme id-ns /dev/nvme0 -n 1
# nvme id-ns /dev/nvme0n1 -n 1
# nvme id-ns /dev/nvme0 --namespace-id=1

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

# nvme id-ns /dev/nvme0n1 --vendor-specific
# nvme id-ns /dev/nvme0n1 -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-ns /dev/nvme0n1 --raw-binary > id_ns.raw
# nvme id-ns /dev/nvme0n1 -b > 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 /dev/nvme0n1 --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.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->nsze);
printf("ncap : %#llx\n", ns->ncap);
return 0;
}

NVME

Part of the nvme-user suite

Use nvme-id-ns online using onworks.net services