Ako vypocitat pocet I/O operacii disku?

From time to time i spend time looking for information how to calculate IOPS (or IO operations per second) for hard drives.

In the following table i outlined how to calculate the IOPS a disk can handle. For this calculation you need at least TWO values. Most of the time you will be given with the RPMs (rotations per minute) and average seek time. You can also cope with rotation latency or IO time – you just need to play with the formulas.



Based on this approach you can easily calculate the data transfer rate (MBPS):



As you can easily see larger IO requests yield to a higher throughput in MBPS. Due to this fact oracle recommends the SAME principle (SAME = stripe and mirror everything) with a stripe size of 1 MB.

Zdroj:
Calculate IOPS (or IO/s) for hard disks
http://ronnyegner.wordpress.com/2009/09/23/calculate-iops-or-ios-for-hard-disks/