19 / 2016-07-15 20:16:54

Adaptive Standard Deviation Based Disk Scheduling Algorithm

Disk Scheduling,First Come First Serve,Standard Deviation,LOOK,SCAN

Hard drives are one of the slowest parts of the computer. A computer deals with multiple requests over a period of time. These multiple requests results in a list where the request line builds up. For efficiency purposes all these requests are aggregated together. The technique that the computer uses to decide which request has to be satisfied first is determined by the disk scheduling algorithms. Presently there are some standard algorithms that are used for Disk scheduling namely First Come First Serve (FCFS), Shortest Job First (SJF), Elevator (SCAN), Circular Scan (C-SCAN), Look and C-Look. This paper provides an alternative to the above mentioned algorithms by using the Standard deviation of the values given. First an array is taken and stores the absolute difference of the Standard deviation value with each individual value. Next another array is taken and this stores the absolute difference of the current position of the head and the first array. The head moves to the position where the second array has minimum value. Then a new standard deviation value is calculated for the remaining values and the algorithm is repeated till complete execution occurs.