By default, Centos 7 doesn’t support Intel’s 10G SFP+ X520 module. When you look at the dmesg you find the following error: “failed to load because an unsupported SFP+ or QSFP module type was detected.” The workaround is to allow unsupported SFP modules in the kernel by enabling ixgbe kernel module. Let’s start by editing /etc/default/grub file and
change the line :
# note the space between " and ixgbe.
Now, we create the new grub configuration with the new option.
cp /boot/grub2/grub.cfg /boot/grub2/grub.cfg.bak
grub2-mkconfig -o /boot/grub2/grub.cfg
Next, the configuration file for the ixgbe kernel module must be created with the option to allow unsupported SFP. The file should not already exist. The one-liner command is:
echo "options ixgbe allow_unsupported_sfp=1" > /etc/modprobe.d/ixgbe.conf
The last step is to regenerate the initrd image with the new kernel configuration and reboot.
dracut --regenerate-all --force
After the reboot, the SFP should be recognized and ready for use.