NVME-DIR-SEND(1) NVMe Manual NVME-DIR-SEND(1)

nvme-dir-send - Issue a directive send command, returns applicable results

nvme dir-send <device> [--namespace-id=<nsid> | -n <nsid>]
                        [--data-len=<data-len> | -l <data-len>]
                        [--dir-type=<dtype> | -D <dtype>]
                        [--dir-spec=<dspec> | -S <dspec>]
                        [--dir-oper=<doper> | -O <doper>]
                        [--endir=<endir> | -e <endir>]
                        [--target-dir=<tdir> | -T <tdir>]
                        [--human-readable | -H] [--raw-binary | -b]
                        [--output-format=<fmt> | -o <fmt>] [--verbose | -v]

Submits an NVMe Directive Send admin command and returns the applicable results. This may be the combination of directive type, and operation, as well as target directive and its enable/disable status of the operation, if specific operation needs it.

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 directive’s parameter structure (if applicable) is returned in one of several ways depending on the option flags; the structure may parsed by the program and printed in a readable format if it is a known structure, displayed in hex, or the raw buffer may be printed to stdout for another program to parse.

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

Retrieve the feature for the given nsid. This is optional and most features do not use this value.

-D <dtype>, --dir-type=<dtype>

Directive type

-S <dspec>, --dir-spec=<dspec>

Directive specific

-O <doper>, --dir-oper=<doper>

Directive operation

-T <tdir>, --target-dir=<nsr>

Target directive of the operation

-e <endir>, --endir=<endir>

Target directive enable(1) or disable (0) operation
Select Description
0 Current
1 Default
2 Saved
3 Supported capabilities
4–7 Reserved

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

The data length for the buffer returned for this feature. Most known features do not use this value. The exception is LBA Range Type

-b, --raw-binary

Print the raw receive buffer to stdout if the command returns a structure.

-H, --human-readable

Print the decoded receive buffer to stdout if the command returns a structure.

-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.

•Enable streams directive : 
# nvme dir-send /dev/nvme0n1 --dir-type 0 --dir-oper 1 --target-dir 1 --endir 1
•Disable streams directive : 
# nvme dir-send /dev/nvme0n1 --dir-type 0 --dir-oper 1 --target-dir 1 --endir 0
•Release all allocated streams resource : 
# nvme dir-send /dev/nvme0n1 --dir-type 1 --dir-oper 2
•Release stream ID 3 : 
# nvme dir-send /dev/nvme0 --dir-type 1 --dir-oper 1 --dir-spec 3

It is probably a bad idea to not redirect stdout when using this mode.

Part of the nvme-user suite

02/16/2024 NVMe