Repost from the JMeter forum:

Hi all, I'm a noob around here, looking for some advice and/or guidance on setting up virtual servers for running JMeter load testing against other virtual servers. Here's the deal:

I am not a programmer, but I'm a decent copycat. I am a QA tester for a company that develops Java web servlets, typically running out of Tomcat but we have some WebLogic deployments as well. I have JMeter scripts that a coworker gave me that I have been tweaking to run on some specific projects I am assigned to. One of these is to develop load test capabilities for blasting high volume of HTTP requests into a new servlet we are developing.

Back when I was running JMeter on my local laptop through VPN into our data center in a remote location, I could get the test to complete in the allotted time. Before our load test got to be such a large JMeter script this was a fairly routine practice. Recently I have been given creds to use virtual servers located in the data center. I have installed JMeter v2.5 with Tomcat JRE 7u51 and run a few tests but I am having no luck getting these virtuals to perform on par with my laptop. My big load test script will complete in less than 24 hours from my laptop, but it takes twice as long to make the run from the virtual installations. My Ops guys are looking into beefing up the performance in the virtuals but they are asking me some nosy questions about my implementation of the load test and they want me to find out if my JMeter could be the problem and not their servers. So, here I am, snooping around for what information I can find that might improve my testing.

My JMeter script runs 25 thread groups with anywhere from 17-81 IfControllers with a two HTTP requests each. To reach the daily volume required I have balanced the thread counts on each group to match expected production loads, the entire script is currently sitting at 800 threads in the originating virtuals when running at full speed. The virtuals are configured for dual-core/multi-CPU and I think 4GHz of CPU speed, 8G of RAM apiece. There is a bunch more config data I have heard but not being an expert in VMware I can't quote the specs from memory.

I am looking for someone who might have experience in this sort of environment who can offer me guidance on the virtual configs that I can pass back over to my Ops guys, or maybe somebody who might give me some advice on making my JMeter run more efficiently. Right now I am about to test it in the non-GUI mode to see if that improves performance, but I won't be able to start that test until a day or two from now.

So, that's my tale of misery I know there is somebody out there in the community who has dealt with these same issues and might give me just the nugget of knowledge I need to make this turkey fly!

As always, advice/guidance/taunts/insults always welcome. Thanx.