Which of the following disk scheduling strategies is likely to give the best throughput?
Farthest cylinder next
Nearest cylinder next
First come first served
Option (B) and (D) both are acceptable. For more details please check comment of @Vicky rix ji.
@tusharp It should be minimum head movements not maximum as overall seek latency is minimum when head movements are minimum thus maximum throughput.
Correct Answer: $B$
Hi @sushmita, vaishali jhalani and Puja Mishra ji,
First of all thanks for raising good point. But could you please provide some counter example where Elevator algorithm will perform better then Nearest cylinder next ?
As long as the block request string is given, we cannot decide between B) and D)
B) is not always the best EX:
throughput put depends on the number of requests served per second as we always go for the shortest reach SSTF Does this best as it tries to serve the maximum number of processes in less time
Thank you @Vicky rix ji.
For more reference go to this question.
How SCAN Algo hear move one side head and then return.
Both B AND D are correct.
D is also correct(see @Vicky rix comment ) and as it's a GATE 1999 question multiple options are possible as answers.
I dont think there can be 2 correct answers for this as it is asking for the BEST, how can two strategies be best simultaneously. What to write if it appears in the exam now…. Other sites like GFG have also given B
The only catch in the question is that they are asking for the most likely to give the best throughput.
Even if for some cases SCAN can have better results but the most likely to result the best throughput is Nearest cylinder Algo ;)