At times when I boot my computer, my external hard drives will indicate disk activity before Grub loads. At this stage when the external drives blink, there is a blinking underscore displayed on the monitor so I'm guessing GRUB does this. The process can be quite slow as I have an external hard drive that spins down after no hard disk activity.
If this process is mandatory in order to identify bootable devices, is there a way to blacklist my external hard disk? Perhaps my external hard drive accidently has bootloader code and is prompted grub to further identify any potential operating systems?