Look Scheduling
Look Scheduling is a disk scheduling algorithm that shares similarities with the SCAN scheduling algorithm. However, it differs in a significant way: in Look Scheduling, the disk arm halts its movement inwards (or outwards) when there are no more pending requests in that direction. This algorithm is designed to address the inefficiency of the SCAN algorithm, which compels the disk arm to continue moving in one direction, even if there are no more requests in that direction.
C-Look Scheduling
C-Look Scheduling, also known as Circular Look Scheduling, bears some resemblance to the C-SCAN algorithm. In this algorithm, the disk arm initially moves outwards to service requests until it reaches the highest requested cylinder. It then jumps to the lowest requested cylinder without servicing any requests before resuming its outward movement to handle the remaining requests.
The key distinction between C-Look and C-SCAN lies in their approach to cylinder visits. C-SCAN forces the disk arm to move to the last cylinder, regardless of whether there are pending requests on that cylinder or not. In contrast, C-Look optimizes the process by not moving to a cylinder if no requests need servicing, thus enhancing efficiency.
In summary, Look Scheduling and C-Look Scheduling are disk scheduling algorithms that optimize the movement of the disk arm, specifically by avoiding unnecessary movements when no requests exist in a certain direction. This approach improves efficiency and response times in comparison to SCAN and C-SCAN algorithms.