topic Re: IOmeter parameters in ONTAP Discussions

IOmeter parameters

yb_benjamin — Wed, 04 Jun 2025 10:56:30 GMT

Hi everybody !

I'm trying to use IOmeter to test a new AFF220 metrocluster.

However, i don't really know which parameters to use to test it...

How many workers should i use ?

I don't really know what is Tranfert Request Size, Align I/Os if you have any ideas ?

I did a try with 4K 100% random on a windows VM with 10 workers. Display results are showing 36K IOPS, however, on the LUN where resides the VM, can't go over 2000 IOPS.. Don't get that !

Thanks !

Re: IOmeter parameters

AlexDawson — Mon, 24 Aug 2020 03:35:45 GMT

Hi there!

Synthetic IOPS Testing is not.. a great measure of anything. Have a view of this video for a bit of a discussion about why - https://www.youtube.com/watch?v=Gfg1pNMCqUQ

Are you concerned by the performance of your system? or rather, what brings you to want to test?

Re: IOmeter parameters

yb_benjamin — Mon, 24 Aug 2020 09:49:55 GMT

Hello,

Thanks for your answer.

I just wanted to guarantee that the metrocluster supports for example 30K IOPs. However, we don't have that much VMs on it so wanted to use a tool to "stress" the metrocluster to see how it goes.

Thanks

Re: IOmeter parameters

AlexDawson — Tue, 25 Aug 2020 05:49:28 GMT

Here we come to the problem of IO speed tests.

As you say, you have run one test which shows 36,000 IOPS, therefore, it can do 30,000+ IOPS.

What is the difference between the networking, connection etc of that test and the one which shows 4,000 IOPS?

Re: IOmeter parameters

yb_benjamin — Tue, 25 Aug 2020 15:09:54 GMT

Hello,

Yes i can see 36K IOPs from the IOmeter application.

However, when i had a look on the LUN where we simulated IOPs, i can't go over 2K IOPs.

Wanted to understand what could explain this difference... I tried to had a look as well on the volume or aggregate and same problem.

Regards ;