Deans Blog

Whilst playing around with Storage I/O control (SIOC) in my vSphere 5 lab environment, I found myself trying to calculate the IOPS to be used when limiting a virtual disk throughput to a certain amount of MBps

So here is the calculation I was using:

IOPS = (MBps Throughput / KB per IO) * 1024 

So using the above, if I wanted to configure an IOPS limit to satisfy a 10 MBps throughput using a 8KB IO request size I would require to set the SIOC IOPS limit to 1280.

IOPS = (10/8)*1024 = 1280

It is possible to use the calculation in reverse to determine the MBps required to achieve the  IOPS claim using the following:

MBps = (IOPS * KB per IO) /1024 

In the above example where the requirement is to achieve 1280 IOPS, we would need a throughput of 10MBps to satisfy that claim.

MBps = (1280 * 8) /1024 = 10