During the boot phase of your virtual machine you may see an error message similar to:

Applying Intel CPU microcode update: FATAL: Module microcode not found.
ERROR: Module microcode does not exist in /proc/modules

As the virtual machine is running on virtual CPUs there is no point updating the microcode. Disabling the microcode update for your virtual machines will stop this error:

/sbin/service microcode_ctl stop
/sbin/chkconfig --del microcode_ctl