SYNOPSIS

nvme [<global-options>] id ns-lba-format <device>
                        [--uuid-index=<uuid-index> | -U <uuid_index>]
                        [--lba-format-index=<lba_format_index> | -i <lba_format_index>]

DESCRIPTION

For the NVMe device given, sends an identify namespace for the specified LBA Format index command and provides the result that is include capability field only 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.

The bare nvme id-ns-lba-format form (without a space) still works as a deprecated alias and will be removed in a future major version. New scripts should use nvme id ns-lba-format instead.

OPTIONS

-U <uuid-index>
--uuid-index=<uuid-index>

UUID Index of the feature

-i <lba_format_index>
--lba-format-index=<lba_format_index>

This field specifies the index into the LBA Format list identifying the LBA Format capabilities that are to be returned

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. Other versions are rejected.

--quiet

Suppress informational messages. Errors are still reported, and --quiet cancels any --verbose for the library log level.

--set-options=<key=value>[,<key=value>…]

Set libnvme library options for this invocation. Supported keys are force-4k, mi-probe-enabled, test-base-dir and test-sysfs-dir.

--timeout=<ms>

Set the timeout for the command in milliseconds. infinite or -1 waits without a time limit (0xffffffff).

-v
--verbose

Increase the level of detail in the output. May be specified multiple times to further increase verbosity.

These options can also be set as machine-wide defaults in nvme-cli.conf(5). A command-line flag always overrides the file.

EXAMPLES

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

    # nvme id ns-lba-format /dev/nvme0n1 -i 0

  • Have the program return the raw structure in binary: 

    # nvme id ns-lba-format /dev/nvme0n1 -i 0 -o binary > id_ns.raw
# nvme id ns-lba-format /dev/nvme0n1 -i 0 --output-format=binary > 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-lba-format /dev/nvme0n1 -i 0 --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_lba_format.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->nlbaf);
        printf("ncap : %#llx\n", ns->mc);
        return 0;
}

NVME

Part of the nvme-user suite