0 votes 0 votes Why is rotational latency usually not considered in disk scheduling ? How would you modify $SSTF$, $SCAN$, and $C-SCAN$ to include latency optimization ? Operating System galvin operating-system disk-scheduling descriptive + – akash.dinkar12 asked Mar 22, 2019 • edited Mar 22, 2019 by akash.dinkar12 akash.dinkar12 1.5k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes Most disks do not export their rotational position information to the host. Even if they did, the time for this information to reach the scheduler would be subject to imprecision and the time consumed by the scheduler is variable, so the rotational position information would become incorrect. Further, the disk requests are usually given in terms of logical block numbers, and the mapping between logical blocks and physical locations is very complex. Ref: https://codex.cs.yale.edu/avi/os-book/OS9/practice-exer-dir/10-web.pdf smsubham answered Mar 17, 2020 smsubham comment Share Follow See all 0 reply Please log in or register to add a comment.