NVME-FABRICS.CONF(5)              NVMe Manual             NVME-FABRICS.CONF(5)

NAME
       nvme-fabrics.conf - NVMe-oF connection configuration file format

SYNOPSIS
       /etc/nvme/nvme-fabrics.conf
       /etc/nvme/nvme-fabrics.conf.d/*.conf

DESCRIPTION
       An INI-format file describing which NVMe over Fabrics (NVMe-oF)
       controllers a host should connect to, and with what parameters. This
       file is read by nvme connect-all, nvme discover and nvme connect, and
       by the nvme-discoverd daemon.

       Other orchestrators read the same format through the same parser, but
       from a file of their own: nvme-stas reads its configuration through the
       Python bindings. The file name is a parameter of every entry point, so
       each orchestrator names its own and is unaffected by the others'.

       A configuration is a main file plus an optional drop-in directory, the
       same foo.conf + foo.conf.d/ pattern systemd uses. Both parts are read
       independently, and either may be absent; an absent configuration is not
       an error; it simply yields no connections.

       --config FILE (on connect-all/discover/connect) names the main file;
       its drop-in directory is always FILE.d/. Omitting --config uses the
       default path above.

SECTIONS
       Each section is one or more key = value lines. An empty value (key =)
       resets the key to the kernel default, overriding whatever an outer
       scope set (see RESETTING A KEY below). Unknown keys are ignored.
       Boolean values accept 1/yes/y/true/t/on and 0/no/n/false/f/off
       (case-insensitive).

       [Host]
           Optional, at most one per file. The identity used by every
           connection in that file: hostnqn, hostid, hostsymname, plus any
           SECURITY key below. A file with no [Host] connects as the system
           default identity (/etc/nvme/hostnqn / hostid). A drop-in that
           defines [Host] must set hostnqn explicitly.

       [Discovery Controller Defaults], [I/O Controller Defaults]
           Optional, at most one of each per file. Default TUNABLE values for
           connections of that class, drawn from below. A drop-in's copy
           overlays the top-level file's, for that drop-in's own connections
           only.

       [Discovery Controller]
           One Discovery Controller to connect to. Repeatable.  nqn = defaults
           to the well-known discovery NQN if omitted.

       [Subsystem]
           One I/O subsystem to connect to, named by nqn =. Repeatable.

       Both endpoint sections accept any TUNABLE or SECURITY key as a
       per-section override, plus one or more controller = lines (below).

CONTROLLER LINES
       Each controller = line under a [Discovery Controller] or [Subsystem]
       section is one path to that endpoint; repeating the key expresses
       multipath (native NVMe multipath groups all paths sharing a subsysnqn).
       The value is a ;-separated key=value list:

           controller = transport=tcp;traddr=10.0.0.9;trsvcid=4420;host-iface=eth0

       transport and traddr are required; trsvcid, host-traddr and host-iface
       are optional. Any TUNABLE key may also appear on the line as a per-path
       override -- SECURITY keys may not, since they are bound to the (host,
       subsystem) pair, not to a single path.

KEYS
       TUNABLE (type default, [Host], endpoint section, or controller = line):

           nr-io-queues, nr-write-queues, nr-poll-queues, queue-size,
           keep-alive-tmo, reconnect-delay, ctrl-loss-tmo, fast-io-fail-tmo,
           tos, duplicate-connect, disable-sqflow, hdr-digest, data-digest

       SECURITY ([Host] or endpoint section only, never a controller = line):

           tls, tls-key, tls-key-identity, keyring, concat, kxchap-secret,
           kxchap-ctrl-secret

       IDENTITY ([Host] only):

           hostnqn, hostid, hostsymname

       Every key here is the same name as its nvme connect long option
       (hyphenated). See nvme-connect(1) for what each one means.

RESETTING A KEY
       An empty assignment (key =) resets that key to the kernel default,
       undoing whatever an outer scope (a *Defaults section or [Host]) set.
       This differs from simply not writing the key, which instead inherits
       through the cascade below.

PRECEDENCE
       A key resolves most-specific first:

           controller = line > endpoint section > [Host] > type defaults > kernel default

       The type-defaults level is chosen by the connection's class: a
       Discovery Controller draws from [Discovery Controller Defaults], an I/O
       Controller from [I/O Controller Defaults].

EXAMPLE
           # /etc/nvme/nvme-fabrics.conf

           [Discovery Controller Defaults]
           keep-alive-tmo = 30

           [I/O Controller Defaults]
           keep-alive-tmo = 5

           [Host]
           hostsymname = lab-host-01

           [Discovery Controller]
           controller = transport=tcp;traddr=192.168.1.10;trsvcid=8009

           [Subsystem]
           nqn        = nqn.2024-01.com.example:data.vol1
           controller = transport=tcp;traddr=192.168.1.20;trsvcid=4420
           controller = transport=tcp;traddr=192.168.1.21;trsvcid=4420

       See /etc/nvme/nvme-fabrics.conf.sample for a longer, commented example.

SEE ALSO
       nvme-connect-all(1) nvme-discover(1) nvme-connect(1)
       nvme-config-convert(1)
       https://github.com/linux-nvme/nvme-cli/blob/master/libnvme/design/CONFIG.md

NVME
       Part of the nvme-user suite

NVMe                              09/07/2026              NVME-FABRICS.CONF(5)