title: where is disk scheduling implemented
body: <p>I'm recently learning the part of <em>disk scheduling</em>of operating system. And I could understand the various algorithms for this issue, like FCFS, LIFO, SSTF, SCAN and so on. But I was wondering where these algorithms are implemented? </p>
  
  <p>I don't think operating system is the answer because OS can't know the details of the I/O devices. So are they implemented on the devices themselves? Could anyone clarify it for me? Any related literature or links will be appreciated.</p>