nvme-io-passthru - Man Page

nvme-io-passthru <device> [--opcode=<opcode> | -O <opcode>]
                        [--flags=<flags> | -f <flags>] [-rsvd=<rsvd> | -R <rsvd>]
                        [--namespace-id=<nsid> | -n <nsid>] [--cdw2=<cdw2> | -2 <cdw2>]
                        [--cdw3=<cdw3> | -3 <cdw3>] [--cdw10=<cdw10> | -4 <cdw10>]
                        [--cdw11=<cdw11> | -5 <cdw11>] [--cdw12=<cdw12> | -6 <cdw12>]
                        [--cdw13=<cdw13> | -7 <cdw13>] [--cdw14=<cdw14> | -8 <cdw14>]
                        [--cdw15=<cdw15> | -9 <cdw15>]
                        [--data-len=<data-len> | -l <data-len>]
                        [--metadata-len=<len> | -m <len>]
                        [--read | -r] [--write | -w]
                        [--input-file=<file> | -i <file>]
                        [--metadata=<file> | -M <file>]
                        [--timeout=<timeout> | -t <timeout>] [--show-command | -s]
                        [--dry-run | -d] [--raw-binary | -b]
                        [--prefill=<prefill> | -p <prefill>]
                        [--latency | -T]
                        [--output-format=<fmt> | -o <fmt>] [--verbose | -v]

Submits an arbitrary NVMe IO command and returns the applicable results. This may be the simply the command’s result and status, or may also include a buffer if the command returns one. This command does no interpretation of the opcodes or options.

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 returned structure (if applicable) may be returned in one of several ways depending on the option flags; the structure may printed by the program as a hex dump, or may be returned as a raw buffer printed to stdout for another program to parse.

-O <opcode>, --opcode=<opcode>

The NVMe opcode to send to the device in the command

-f <flags>, --flags=<flags>

The NVMe command flags to send to the device in the command

-R <rsvd>, --rsvd=<rsvd>

The value for the reserved field in the command.

-n <nsid>, --namespace-id=<nsid>

The value for the ns-id in the command. Defaults to 0.

-[2-9] <cdw>, --cdw[2-3,10-15]=<cdw>

Specifies the command dword value for that specified entry in the command

-r,  --read,  -w,  --write

Used for the data-direction for the command and required for commands sending/receiving data. Don’t use both read and write at the same time.

-i <file>, --input-file=<file>

If the command is a data-out (write) command, use this file to fill the buffer sent to the device. If no file is given, assumed to use STDIN. If the command is a data-in (read) command, the data returned from the device will be saved here.

-M <file>, --metadata=<file>

If the command is a data-out (write) command, use this file to fill the metadata buffer sent to the device. If no file is given, assumed to use STDIN. If the command is a data-in (read) command, the metadata returned from the device will be saved here.

-l <data-len>, --data-len=<data-len>

The data length for the buffer used for this command.

-m <data-len>, --metadata-len=<data-len>

The metadata length for the buffer used for this command.

-s,  --show-cmd

Print out the command to be sent.

-d,  --dry-run

Do not actually send the command. If want to use --dry-run option, --show-cmd option must be set. Otherwise --dry-run option will be ignored.

-b,  --raw-binary

Print the raw returned buffer to stdout if the command returns data or a structure.

-p <prefill>, --prefill <prefill>

Prefill the buffer with a predetermined byte value. Defaults to 0. This may be useful if the data you are writing is shorter than the required buffer, and you need to pad it with a known value. It may also be useful if you need to confirm if a device is overwriting a buffer on a data-in command.

-T,  --latency

Print out the latency the IOCTL took (in us).

-o <fmt>, --output-format=<fmt>

Set the reporting format to normal, json or binary. Only one output format can be used at a time.

-v,  --verbose

Increase the information detail in the output.

-t <timeout>, --timeout=<timeout>

Override default timeout value. In milliseconds.

nvme io-passthru /dev/nvme0n1 --opcode=2 --namespace-id=1 --data-len=4096 --read --cdw10=0 --cdw11=0 --cdw12=0x70000 --raw-binary

Part of the nvme-user suite

nvme(1).