IOMeter testing says the IOPs of the storage subsystem can range from hundreds of IOPs for 100% random loads to tens of thousands IOPs for 100% sequential loads.
Is there any way I can measure or estimate the random/sequential distribution of the IO we actually have coming from a mix of servers on VMware ESX hosts?
From the SAN, I can get stats about Read Percentage, about Read cache hit rate, and about current IO counts. That says we've got ~40% read / 60% write distribution, and averaging 1,000 IOPs varying from lows of 350 to highs of 2,100.
The Read Cache hit rate is very variable, it goes <1% up to 80%, and averages 36%. Can I use that variability to conclude anything about the randomness of the IO, or is that not a good correlation?