This I know is probably a dumb question, plus being new to this does not help. I have four 4TB WD red running in RaidZ and every 5 seconds drive led lights and you can hear drive noise, all in a second, than it occurs again and again, every 5 seconds or thereabout. Is this something in FreeNas accessing or checking every 5 seconds? Just need a yes or no. If yes, what is accessing the drive.