'\" t
.\"     Title: nvme-connect
.\"    Author: [see the "AUTHORS" section]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 10/30/2026
.\"    Manual: NVMe Manual
.\"    Source: NVMe
.\"  Language: English
.\"
.TH "NVME\-CONNECT" "1" "10/30/2026" "NVMe" "NVMe Manual"
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.SH "NAME"
nvme-connect \- Connect to a Fabrics controller\&.
.SH "SYNOPSIS"
.sp
.nf
\fInvme\fR [<global\-options>] \fIconnect\fR [\-\-config=<filename>]
                        [\-\-devid\-file=<filename>]
                        [\-\-discovery]
                        [\-\-idempotent]
                        [\-\-owner=<NAME>]
                        [<fabrics\-options>]
.fi
.SH "DESCRIPTION"
.sp
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\&.
.SH "OPTIONS"
.PP
\-\-config=<filename>
.RS 4
Use the specified JSON configuration file instead of the default\&.
.RE
.PP
\-\-devid\-file=<filename>
.RS 4
Write the kernel\-assigned device name (for example, nvme0) to <filename>\&. If the controller is already connected, the existing device name is written\&. Otherwise, the device name is written after the controller is connected\&.
.sp
.if n \{\
.RS 4
.\}
.nf
When used with \-\-idempotent, the existing device name is written
before the command exits successfully\&. This allows a supervising
process, such as a systemd service, to identify the device for a
later disconnect operation\&.
.fi
.if n \{\
.RE
.\}
.sp
.if n \{\
.RS 4
.\}
.nf
The output file is created before attempting the connection\&. If
the file cannot be created, for example because the parent
directory does not exist, the command fails without attempting
the connection\&.
.fi
.if n \{\
.RE
.\}
.RE
.PP
\-\-discovery
.RS 4
The target is a Discovery Controller\&. The kernel recognizes the well\-known discovery NQN by itself, but sees a Discovery Controller with a unique NQN as an I/O controller without this option\&. That gives it a keep\-alive timeout of 5 seconds when none is given, and creates I/O queues for it\&.
.RE
.PP
\-\-idempotent
.RS 4
Exit with status 0 if the requested controller is already connected instead of reporting an error\&.
.RE
.PP
\-\-owner=<NAME>
.RS 4
Record NAME as the owner of the connected controller in the NVMe ownership registry, so other orchestrators (and nvme\-disconnect\-all) leave it alone\&. See nvme\-disconnect\-all(1)\&. An empty NAME (\-\-owner=) removes the registry entry instead, leaving the controller unowned\&. Without \-\-owner, a controller that was already connected keeps the entry it has\&.
.RE
.SH "FABRICS OPTIONS"
.sp
The following options are common to NVMe over Fabrics commands such as nvme connect:
.PP
\-a <traddr>, \-\-traddr=<traddr>
.RS 4
Specify the network address of the controller\&. For transports using IP addressing (e\&.g\&. rdma, tcp), this should be an IP address\&.
.RE
.PP
\-\-concat
.RS 4
Enable secure concatenation (TCP)\&.
.RE
.PP
\-c <#>, \-\-reconnect\-delay=<#>
.RS 4
Set the delay in seconds before reconnect is attempted after a connection loss\&.
.RE
.PP
\-C <secret>, \-\-kxchap\-ctrl\-secret=<secret>
.RS 4
Controller authentication secret for bi\-directional authentication\&. If not specified, bi\-directional authentication is not attempted\&.
.RE
.PP
\-S <secret>, \-\-kxchap\-secret=<secret>
.RS 4
Host authentication secret (KX\-HMAC\-CHAP)\&. Must be provided in ASCII format as defined in the NVMe specification\&.
.RE
.PP
\-C <secret>, \-\-dhchap\-ctrl\-secret=<secret>
.RS 4
Controller authentication secret for bi\-directional authentication\&. If not specified, bi\-directional authentication is not attempted\&. (deprecated, see \-\-kxchap\-ctrl\-secret)
.RE
.PP
\-S <secret>, \-\-dhchap\-secret=<secret>
.RS 4
Host authentication secret (DH\-HMAC\-CHAP)\&. Must be provided in ASCII format as defined in the NVMe specification\&. (deprecated, see \-\-kxchap\-secret)
.RE
.PP
\-\-disable\-sqflow
.RS 4
Disable submission queue flow control\&.
.RE
.PP
\-G, \-\-data\-digest
.RS 4
Enable data digest generation/verification (TCP)\&.
.RE
.PP
\-D, \-\-duplicate\-connect
.RS 4
Allow duplicate connections to the same subsystem\&.
.RE
.PP
\-g, \-\-hdr\-digest
.RS 4
Enable header digest generation/verification (TCP)\&.
.RE
.PP
\-f <iface>, \-\-host\-iface=<iface>
.RS 4
Specify the network interface to use for the connection\&.
.RE
.PP
\-I <hostid>, \-\-hostid=<hostid>
.RS 4
Specify the host UUID\&.
.RE
.PP
\-q <hostnqn>, \-\-hostnqn=<hostnqn>
.RS 4
Override the default host NQN\&.
.RE
.PP
\-w <traddr>, \-\-host\-traddr=<traddr>
.RS 4
Specify the source address on the host side of the connection\&.
.RE
.PP
\-k <#>, \-\-keep\-alive\-tmo=<#>
.RS 4
Set the keep\-alive timeout in seconds\&.
.RE
.PP
\-\-keyring=<keyring>
.RS 4
Keyring to use for TLS key lookup\&.
.RE
.PP
\-n <subnqn>, \-\-nqn=<subnqn>
.RS 4
Specify the NVMe subsystem NQN to connect to\&.
.RE
.PP
\-i <#>, \-\-nr\-io\-queues=<#>
.RS 4
Number of I/O queues to create\&.
.RE
.PP
\-P <#>, \-\-nr\-poll\-queues=<#>
.RS 4
Number of polling queues to create\&.
.RE
.PP
\-W <#>, \-\-nr\-write\-queues=<#>
.RS 4
Number of write queues to create\&.
.RE
.PP
\-Q <#>, \-\-queue\-size=<#>
.RS 4
Queue depth for I/O queues\&.
.RE
.PP
\-l <#>, \-\-ctrl\-loss\-tmo=<#>
.RS 4
Maximum time in seconds to retry reconnect attempts after controller loss\&.
.RE
.PP
\-s <trsvcid>, \-\-trsvcid=<trsvcid>
.RS 4
Transport service identifier (e\&.g\&. TCP/rdma port)\&. Default is 4420 for RDMA\&.
.RE
.PP
\-T <#>, \-\-tos=<#>
.RS 4
Type of service value for the connection (TCP)\&.
.RE
.PP
\-t <trtype>, \-\-transport=<trtype>
.RS 4
Specify the transport type\&. Supported values include:
.RE
.sp
+
.TS
allbox tab(:);
lt lt
lt lt
lt lt
lt lt
lt lt.
T{
.sp
Value
T}:T{
.sp
Description
T}
T{
.sp
rdma
T}:T{
.sp
RDMA (RoCE, iWARP, InfiniBand)
T}
T{
.sp
tcp
T}:T{
.sp
TCP/IP
T}
T{
.sp
fc
T}:T{
.sp
Fibre Channel (\fBexperimental\fR)
T}
T{
.sp
loop
T}:T{
.sp
Local loopback transport
T}
.TE
.sp 1
.PP
\-\-tls
.RS 4
Enable TLS encryption (TCP)\&.
.RE
.PP
\-\-tls\-key=<tls\-key>
.RS 4
TLS key for the connection\&. It is recommended to preload keys into the system keyring instead of passing them via the command line\&.
.RE
.PP
\-\-tls\-key\-identity=<identity>
.RS 4
Identity associated with the TLS key\&.
.RE
.SH "GLOBAL OPTIONS"
.sp
The following options are defined at the top\-level nvme command and are available to this subcommand:
.PP
\-\-dry\-run
.RS 4
Print the command that would be executed, but do not actually execute it\&.
.RE
.PP
\-\-no\-ioctl\-probing
.RS 4
Disable probing for 64\-bit IOCTL support\&.
.RE
.PP
\-\-no\-retries
.RS 4
Disable retry logic on transient errors\&.
.RE
.PP
\-o <fmt>, \-\-output\-format=<fmt>
.RS 4
Set the reporting format to
\fInormal\fR,
\fItabular, \*(Aqjson\fR, or
\fIbinary\fR\&. Only one output format may be used at a time\&.
.RE
.PP
\-\-output\-format\-version=<version>
.RS 4
Select the output format version\&. Version
\fI1\fR
uses the original field naming, while version
\fI2\fR
(default) provides more consistent and script\-friendly field names\&. Other versions are rejected\&.
.RE
.PP
\-\-quiet
.RS 4
Suppress informational messages\&. Errors are still reported, and \-\-quiet cancels any \-\-verbose for the library log level\&.
.RE
.PP
\-\-set\-options=<key=value>[,<key=value>\&...]
.RS 4
Set libnvme library options for this invocation\&. Supported keys are
\fIforce\-4k\fR,
\fImi\-probe\-enabled\fR,
\fItest\-base\-dir\fR
and
\fItest\-sysfs\-dir\fR\&.
.RE
.PP
\-\-timeout=<ms>
.RS 4
Set the timeout for the command in milliseconds\&.
\fIinfinite\fR
or
\fI\-1\fR
waits without a time limit (0xffffffff)\&.
.RE
.PP
\-v, \-\-verbose
.RS 4
Increase the level of detail in the output\&. May be specified multiple times to further increase verbosity\&.
.RE
.sp
These options can also be set as machine\-wide defaults in nvme\-cli\&.conf(5)\&. A command\-line flag always overrides the file\&.
.SH "EXAMPLES"
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
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:
.sp
.if n \{\
.RS 4
.\}
.nf
# nvme connect \-\-transport=rdma \-\-traddr=192\&.168\&.1\&.3 \e
\-\-nqn=nqn\&.2014\-08\&.com\&.example:nvme:nvm\-subsystem\-sn\-d78432
.fi
.if n \{\
.RE
.\}
.RE
.SH "SEE ALSO"
.sp
nvme\-discover(1) nvme\-connect\-all(1)
.SH "AUTHORS"
.sp
This was co\-written by \m[blue]\fBJay Freyensee\fR\m[]\&\s-2\u[1]\d\s+2 and \m[blue]\fBChristoph Hellwig\fR\m[]\&\s-2\u[2]\d\s+2
.SH "NVME"
.sp
Part of the nvme\-user suite
.SH "NOTES"
.IP " 1." 4
Jay Freyensee
.RS 4
\%mailto:james.p.freyensee@intel.com
.RE
.IP " 2." 4
Christoph Hellwig
.RS 4
\%mailto:hch@lst.de
.RE