ReadyNAS Pro Business: Fan spinning often?

Blues wrote:
The fan in my ReadyNAS Pro Business has been tending to spin a lot in the last few weeks and I don't know what the cause is.

Apologies for asking this rather obvious question, but have you cleaned the dust out of the fans and heatsinks? If you haven't, it might really make a difference.

Best way to clean the NAS is to shut it down, open the case, and use a can of compressed air to blow the dust out of the fans and heatsinks (and out of the power supply, and from between the drives, and off the mesh on the front-panel door, etc.). Hold the fan blades still while you're cleaning them; the fan bearings can't withstand high RPMs and will fail if you spin them up with the compressed air.