IOmeter parameters

[yb_benjamin]

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 !

[AlexDawson]

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?

[yb_benjamin]

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

[AlexDawson]

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?

[yb_benjamin]

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 ;