Most disk-based system's performance heavily depends on its disk access patterns. So maximizing the sequential I/Os while avoiding the random I/Os is a typical goal in performance perspective. I am working on the same problem.
I have some difficulties in measuring the degree of randomness of Disk I/Os. I can measure the disk throughputs in MB/sec using the performance monitoring tools. However, MB/sec is a result of such and such possible causes including the disk access patterns. I want to directly measure how much random disk I/Os are occurring at a certain moment.
Is there any metric that is commonly used to represent the degree of randomness in Disk I/Os?
If there is, how can I measure those?