A certain moving arm disk-storage device has the following specifications:
Number of tracks per surface $$=4004$$
Track storage capacity $$=130030$$ bytes
Disk speed $$=3600$$ rpm
Average seek time $$=30$$ m secs.
Estimate the average latency the disk storage capacity and the data transfer rate.

Assuming the current disk cylinder to be $$50$$ and the sequence for the cylinders to be
$$1, 36, 49, 65, 53, 1, 2, 3, 20, 55, 16, 65$$ and $$78$$ find the sequences of servicing using
(i) shortest-seek time first $$(SSTF)$$
(ii) elevator disk scheduling polices.

The highest-response ratio next scheduling policy favours $$.......$$ jobs, but it also limits the waiting time of $$ .....$$ jobs.

Semaphore operations are atomic because they are implemented within the OS