Why fcoe service is unable to start in Red Hat Enterprise Linux 7 ?

Issue

• Unable to start fcoe service on boot time.
• fcoe service is failing to start with the below mentioned messages

[root@hostname multi-user.target.wants]# service fcoe start
Redirecting to /bin/systemctl start  fcoe.service
Job for fcoe.service failed. See 'systemctl status fcoe.service' and 'journalctl -xn' for details.

[root@hostname multi-user.target.wants]# systemctl status fcoe.service
fcoe.service - Open-FCoE Inititator.
   Loaded: loaded (/usr/lib/systemd/system/fcoe.service; enabled)
   Active: failed (Result: exit-code) since Thu 2015-04-16 11:46:22 WEST; 49s ago
  Process: 33657 ExecStartPre=/sbin/modprobe -qa $SUPPORTED_DRIVERS (code=exited, status=1/FAILURE)

Apr 16 11:46:22 hostname systemd[1]: fcoe.service: control process exited, code=exited status=1
Apr 16 11:46:22 hostname systemd[1]: Failed to start Open-FCoE Inititator..
Apr 16 11:46:22 hostname systemd[1]: Unit fcoe.service entered failed state.