nvme-connect - Man Page

nvme connect [--transport=<trtype> | -t <trtype>]
                        [--nqn=<subnqn> | -n <subnqn>]
                        [--traddr=<traddr> | -a <traddr>]
                        [--trsvcid=<trsvcid> | -s <trsvcid>]
                        [--host-traddr=<traddr> | -w <traddr>]
                        [--host-iface=<iface> | -f <iface>]
                        [--hostnqn=<hostnqn> | -q <hostnqn>]
                        [--hostid=<hostid> | -I <hostid>]
                        [--config=<filename> | -J <filename>]
                        [--dhchap-secret=<secret> | -S <secret>]
                        [--dhchap-ctrl-secret=<secret> | -C <secret>]
                        [--nr-io-queues=<#> | -i <#>]
                        [--nr-write-queues=<#> | -W <#>]
                        [--nr-poll-queues=<#> | -P <#>]
                        [--queue-size=<#> | -Q <#>]
                        [--keep-alive-tmo=<#> | -k <#>]
                        [--reconnect-delay=<#> | -c <#>]
                        [--ctrl-loss-tmo=<#> | -l <#>] [--tos=<#> | -T <#>]
                        [--keyring=<keyring>] [--tls-key=<tls-key>]
                        [--tls-key-identity=<identity>]
                        [--duplicate-connect | -D] [--disable-sqflow ]
                        [--hdr-digest | -g] [--data-digest | -G] [--tls]
                        [--concat] [--dump-config | -O] [--application=<id>]
                        [--output-format=<fmt> | -o <fmt>] [--verbose | -v]

Create a transport connection to a remote system (specified by --traddr and --trsvcid) and create a NVMe over Fabrics controller for the NVMe subsystem specified by the --nqn option​.

-t <trtype>, --transport=<trtype>

This field specifies the network fabric being used for a NVMe-over-Fabrics network​. Current string values include:

Value	Definition
rdma	The network fabric is an rdma network (RoCE, iWARP, Infiniband, basic rdma, etc)
fc	WIP The network fabric is a Fibre Channel network​.
tcp	The network fabric is a TCP/IP network​.
loop	Connect to a NVMe over Fabrics target on the local host

-n <subnqn>, --nqn <subnqn>

This field specifies the name for the NVMe subsystem to connect to​.

-a <traddr>, --traddr=<traddr>

This field specifies the network address of the Controller​. For transports using IP addressing (e​.g​. rdma) this should be an IP-based address (ex​. IPv4)​.

-s <trsvcid>, --trsvcid=<trsvcid>

This field specifies the transport service id​. For transports using IP addressing (e​.g​. rdma) this field is the port number​. By default, the IP port number for the RDMA transport is 4420​.

-w <traddr>, --host-traddr=<traddr>

This field specifies the network address used on the host to connect to the Controller​. For TCP, this sets the source address on the socket​.

-f <iface>, --host-iface=<iface>

This field specifies the network interface used on the host to connect to the Controller (e​.g​. IP eth1, enp2s0, enx78e7d1ea46da)​. This forces the connection to be made on a specific interface instead of letting the system decide​.

-q <hostnqn>, --hostnqn=<hostnqn>

Overrides the default Host NQN that identifies the NVMe Host​. If this option is not specified, the default is read from /etc/nvme/hostnqn first​. If that does not exist, the autogenerated NQN value from the NVMe Host kernel module is used next​. The Host NQN uniquely identifies the NVMe Host​.

-I <hostid>, --hostid=<hostid>

UUID(Universally Unique Identifier) to be discovered which should be formatted​.

-J <filename>, --config=<filename>

Use the specified JSON configuration file instead of the default /etc/nvme/config​.json file or none to not read in an existing configuration file​. The JSON configuration file format is documented in https://github​.com/linux-nvme/libnvme/blob/master/doc/config-schema​.json

-S <secret>, --dhchap-secret=<secret>

NVMe In-band authentication secret; needs to be in ASCII format as specified in NVMe 2​.0 section 8​.13​.5​.8 Secret representation​.

-C <secret>, --dhchap-ctrl-secret=<secret>

NVMe In-band authentication controller secret for bi-directional authentication; needs to be in ASCII format as specified in NVMe 2​.0 section 8​.13​.5​.8 Secret representation​. If not present bi-directional authentication is not attempted​.

-i <#>, --nr-io-queues=<#>

Overrides the default number of I/O queues create by the driver​.

-W <#>, --nr-write-queues=<#>

Adds additional queues that will be used for write I/O​.

-P <#>, --nr-poll-queues=<#>

Adds additional queues that will be used for polling latency sensitive I/O​.

-Q <#>, --queue-size=<#>

Overrides the default number of elements in the I/O queues created by the driver​.

-k <#>, --keep-alive-tmo=<#>

Overrides the default keep alive timeout (in seconds)​.

-c <#>, --reconnect-delay=<#>

Overrides the default delay (in seconds) before reconnect is attempted after a connect loss​.

-l <#>, --ctrl-loss-tmo=<#>

Overrides the default controller loss timeout period (in seconds)​. This is the maximum time the kernel will retry a connection, where each retry will be issued after reconnect-delay seconds​.

-T <#>, --tos=<#>

Type of service for the connection (TCP)

--keyring=<keyring>

Keyring for TLS key lookup, either the key id or the keyring name​.

--tls-key=<tls-key>

TLS key for the connection (TCP), either the TLS key in interchange format or the key id​. It’s strongly recommended not to provide the TLS key via the comamnd line due to security concerns​. Instead in production situation, the key should be loaded into the keystore with nvme tls --import and only the --tls options used​. The kernel will select the matching key​.

--tls-key-identity=<identity>

The identity used for the tls-key​. If none is provided the tls-key provided via the comamnd line is considered a configuration key and a derive key will be loaded into the keyring​.

-D,  --duplicate-connect

Allows duplicated connections between same transport host and subsystem port​.

--disable-sqflow

Disables SQ flow control to omit head doorbell update for submission queues when sending nvme completions​.

-g,  --hdr-digest

Generates/verifies header digest (TCP)​.

-G,  --data-digest

Generates/verifies data digest (TCP)​.

--tls

Enable TLS encryption (TCP)​.

--concat

Enable secure concatenation (TCP)​.

-O,  --dump-config

Print out resulting JSON configuration file to stdout​.

--context <STR>

Set the execution context to <STR>​. This allows to coordinate the management of the global resources​.

-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​.

• Connect to a subsystem named nqn​.2014-08​.com​.example:nvme:nvm-subsystem-sn-d78432 on the IP4 address 192​.168​.1​.3​. Port 4420 is used by default:

  # nvme connect --transport=rdma --traddr=192​.168​.1​.3 \
  --nqn=nqn​.2014-08​.com​.example:nvme:nvm-subsystem-sn-d78432

nvme-discover(1) nvme-connect-all(1)

This was co-written by Jay Freyensee​^[1] and Christoph Hellwig​^[2]

Part of the nvme-user suite

1. Jay Freyensee
   mailto:james.p.freyensee@intel.com
2. Christoph Hellwig
   mailto:hch@lst.de

nvme(1), nvme-connect-all(1), nvme-disconnect(1), nvme-discover(1).