I recently queried Pegasus Technical Support why the fan on my new Pegasus 32 R4 kept running after I'd shutdown my computer. They replied that:
"The Pegasus 32 series has a two fan setup, the secondary fan in the Pegasus will continue to run when your MAC is powered off or put to sleep this is by design. In order to have the fan shut off you would need to either power off the Pegasus or disconnect the power cable/thunderbolt to the unit."
The thunderbolt Lacie RAID drives I previously used automatically shutown with the Mac. I am now forced to manually unmount and shutdown the Pegasus drive every time I shutdown my computer; otherise the fan will run for hours or days until I next use the computer again. I then have to manually turn the Pegasus unit back on again when starting up my Mac as it won't power up by itself.
This is a really bad design flaw that hasn't been mentioned in any of the reviews I read.
The support consultant said:
"This is not an error but the design of the unit, I am not sure if this will be changed in a future firmware update but let me share your feedback to our team."
I hope there is some push to update the firmware.