nvme-id-ns(1)
=============

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

SYNOPSIS
--------
[verse]
'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
