Provided by: fcoe-utils_1.0.31+git20160622.5dfd3e4-2_amd64 
NAME
fcoemon - Open-FCoE service daemon
SYNOPSIS
fcoemon [-f|--foreground] [-l|--legacy] [-d|--debug] [-s|--syslog]
fcoemon -h|--help
fcoemon -v|--version
DESCRIPTION
The fcoemon daemon is the core component of the Open-FCoE management service.
The primary function of fcoemon is to control FCoE instances. fcoemon will create, destroy, reset, enable
and disable FCoE instances based on system configuration, administrative commands, and runtime events.
On startup, fcoemon will create FCoE instances defined by the configuration files (see FILES section
below). Since FCoE typically relies on the Data Center Bridging (DCB) capabilities of an Ethernet
interface, fcoemon establishes a connection with the LLDP daemon lldpad to query the status of the DCB
features on relevant Ethernet interfaces and receive DCB configuration change events.
During runtime, fcoemon will monitor network and lldpad events for the relevant Ethernet interfaces and
perform appropriate actions (create, destroy, enable, disable) on the FCoE instances. fcoemon also
provides a client interface via which the fcoeadm utility is able to issue commands.
Installation of the fcoe-utils package will set up an fcoe service which will control the execution of
the fcoemon daemon.
OPTIONS
-f, --foreground
Run fcoemon in the foreground.
-d, --debug
Enable debugging messages.
-l, --legacy
Force fcoemon to use the legacy /sys/module/libfcoe/parameters/ interface. The default is to use the
newer /sys/bus/fcoe/ interfaces if they are available.
-s, --syslog
Use syslogd for logging. The default behavior is to log to stdout and stderr.
-h, --help
Show help message with basic usage instructions
-v, --version
Show the version of the fcoemon command.
TERMINOLOGY
DCB
Data Center Bridging A set of Ethernet enhancement standards developed by the IEEE 802.1 Working
Group.
See http://www.ieee802.org/1/pages/dcbridges.html for more information.
DCBX
DCB Capabilities Exchange Protocol, implemented by the DCB module of lldpad. DCBX exchanges DCB
capabilities and configuration with a link partner as a series of values transferred using the Link
Layer Discovery Protocol (LLDP).
PFC
Priority-based Flow Control, a DCB feature.
App:FCoE
The FCoE instance of application specific parameters in DCBX.
CRITERIA USED FOR CONTROLLING THE FCOE INSTANCE
fcoemon uses two information sources for determining when to create an FCoE instance: the state of the
network interface, which may be a VLAN interface, and, if required for the FCoE instance, the state of
the DCB configuration on the physical Ethernet interface.
First of all, the network interface must be "up" for the FCoE instance to be created. Secondly, if the
FCoE configuration indicates that DCB is required, then the following criteria must be satisfied before
the FCoE interface is created:
• DCB is enabled on the Ethernet interface.
• The PFC DCB feature is enabled and operational.
• The App:FCoE DCB feature is enabled and operational.
• The priority indicated by the App:FCoE feature is also enabled for PFC.
Once the FCoE instance is created by fcoemon, it will only be destroyed under the following conditions:
• The driver for the Ethernet interface is unloaded.
• A user administratively destroys the FCoE instance using fcoeadm.
• The fcoemon daemon is terminated.
If DCB is required for the FCoE instance, and the DCB settings change after the interface is created, the
following criteria are used to disable the FCoE instance:
• DCB is disabled on the Ethernet interface.
• The App:FCoE DCB feature is not enabled.
• The App:FCoE and PFC features are operational AND the priority indicated by App:FCoE is not enabled
for PFC.
Otherwise, the FCoE instance will always remain enabled.
CONFIGURATION
Once the fcoe-utils and lldpad packages have been installed and the corresponding services are running,
there are a few simple configuration steps required to get an FCoE instance up and running. The following
assumes that DCB will be required for the interface.
• Ensure that the configuration on the peer device (e.g. FCoE capable switch) has the necessary
configurations (VLANs, DCB, DCBX).
• Configure any needed VLAN interfaces on the local system.
• Create and configure /etc/fcoe/cfg-<ifname> files for the network interfaces over which FCoE
instances need to be created. See the FILES sections for details. Note that ifname may be for a VLAN
interface.
• Restart the fcoe service (i.e. fcoemon).
• The default DCB configuration of an Ethernet interface managed by lldpad requires the following
configuration using dcbtool.
dcbtool sc ethX dcb on <-- enable DCB on the interface
dcbtool sc ethX app:fcoe e:1 <-- enable App:FCoE on the interface
These steps only need to be done one time. Note that if other DCB configuration changes have been made
with dcbtool, then additional changes may need to be made in order to satisfy the DCB criteria for
creating an FCoE instance. Consult dcbtool for details.
Once these configuration steps have been performed, use fcoeadm to query the status of the FCoE
instances.
FILES
/etc/fcoe/config
This is the primary configuration file for the fcoe system service. The default options in this file are:
DEBUG="no" and USE_SYSLOG="yes". The former is used to enable debugging messages from the fcoe service
script and fcoemon (via the --debug option). The latter is to indicate if the log messages are to be
output to the system log (via the --syslog option). SUPPORTED_DRIVERS is the list of drivers to
automatically load during fcoe service start. Any changes to this file will require a restart of the fcoe
service.
/etc/sysconfig/fcoe
On systemd-enabled systems, this is the primary configuration file used for the fcoe system service. Add
--debug to FCOEMON_OPTS to enable debug log messages. Any changes to this file will require a restart of
the fcoe service.
/etc/fcoe/cfg-<ifname>
These files are read by fcoemon on initialization. They are used to indicate which Ethernet or VLAN
interfaces should have FCoE instances created. The option values in this file normally are:
FCOE_ENABLE="yes", DCB_REQUIRED="yes", and AUTO_VLAN="yes", though if the variable values are omitted,
they default to "no".
FCOE_ENABLE
is used to enable/disable creation of the FCoE instance. If FCoE_ENABLE is set to "no", then the
other configuration values have no effect.
DCB_REQUIRED
indicates if the DCB service is required on the Ethernet interface.
AUTO_VLAN
indicates if VLAN discovery should be performed. If AUTO_VLAN is set to "yes", then once the link
configuration has been validated, fcoemon will run run the FIP VLAN discovery protocol on the
Ethernet interface. Network interfaces for any discovered FCoE VLANs will be automatically created,
if they are not already configured, and FCoE instances will be created on the VLAN interfaces. If the
network interface specified by the filename is already a VLAN interface, the AUTO_VLAN setting is
ignored.
MODE
indicates whether operation will be in fabric or vn2vn mode. The default is fabric.
FIP_RESP
indicates whether a FIP responder should be activated on this device to support VLAN discovery in a
vn2vn environment. The default is "no". Often this will be used on a vn2vn node also serving as a
target. When using this option, the AUTO_VLAN should not be set and the supported VLANs should have
configuration files supplied, constituting a static VLAN configuration that provides the information
for the FIP responder to return. This should be set on a base device, which should probably have
FCOE_ENABLE set to "no" since presumably FCoE operation will be on the configured VLANs.
Note that the attached Ethernet peer device (e.g. FCoE capable switch port) must have compatible settings
For DCB and FCoE to function properly.
/etc/init.d/fcoe
This is the fcoe system service script. This script is invoked by the init process or by the service
command to start and stop the fcoemon. On systemd-enabled systems, fcoemon is controlled via the
fcoe.service unit.
VLAN NAMING CONVENTIONS
If a new VLAN device is created (see the description of the AUTO_VLAN setting above), it will have the
name dev.vlan-fcoe; where dev is the name of the Ethernet parent device and vlan is the discovered VLAN
ID number.
SEE ALSO
fcoeadm(8) lldpad(8) lldptool(8) dcbtool(8)
SUPPORT
fcoemon is part of the fcoe-utils package, maintained through the Open-FCoE project. Resources for both
developers and users can be found at the Open-FCoE website http://open-fcoe.org/