2011 27" iMac Beachball due to external HD

[likegadgets]

I often encounter the beachball delay when opening finder. I am quite sure this happens as finder scans the external hard drives that are connected (I have 3 drives - 2 Firewall and 1 USB 2.0).

There is nothing wrong with the drives - but as the iMac scans - it creates the delay.

Is there anyway to prevent the iMac from scanning the available drives ?

 

[AppleNewton]

Reason for the beachball seems normal. the drives idle and are put into sleep/idle mode where they are not moving/spinning or readily available.
Anytime you open Finder it will wake those drives from idle/sleep mode, hence causing the delay in using finder.