How come a hard drive spins up when I am not accessing it?

by on March 18, 2012

Q: I have a new PC with Windows 7 and one HD in. Recently added another HD in. I can readily access this HD any time I want. Everything works fine. But every so often I hear the PC starts spinning the added HD for no reason. I am not accessing it at the times when this happens. Nothing shows on the screen though.
At the shutdown time (after I hit the Shut Down button or click on the Shut Down tab) it regularly starts the added HD just to turn it off seconds later. Why? I’d like to disable this whole random starting especially at shutdown time but how?

One Response to “How come a hard drive spins up when I am not accessing it?”

    There are a number of reasons why a hard drive that isn’t being accessed would spin up. Operating systems are very interesting pieces of software and they do fun things like storing information in RAM instead of writing to the hard drive to increase speed. This, however, causes funny things like data not being written to the drives when you crash so you lose your data. Because of this operating systems will periodically write the data to the disks when the disks are doing nothing.

    So my gut feeling, without seeing this, is that when your hard drive spins up it is because your operating system has determined that now is a good time to write data to that drive that it has been holding in RAM.