A disk has cylinders numbered 0 to 199. If the C-SCAN head is moving toward higher cylinders and reaches cylinder 199, where does it move next for continuing the circular scan?

Options

  • A. Cylinder 198
  • B. Cylinder 100
  • C. Cylinder 0
  • D. More than one of the above
  • E. None of the above

Correct Answer (Detailed Explanation is Below)

C. Cylinder 0

Detailed Explanation

Explanation: In C-SCAN, after reaching the highest cylinder, the disk head returns to the lowest cylinder and continues servicing requests in the same direction. Therefore, after cylinder 199, it returns to cylinder 0.