Flings in VMware labs is a great place for (very) useful tools or applications. This time I want to blog about a fling I often use in a test phase for implementation projects or in health assessments, see what synthetic load an environment can handle and if your vSphere design is up to the right io charactics and capacity.

Important in these kinds of test is your test methodology and plan: Assess, Filter test, plan, collect, analyse and report. With several of these steps IO Analyzer can be the player.

IO analyzer can configure, schedule and run several IOmeter workloads or replay vSCSI traces.

Download at:


Import ovf to your environment. Start with more then one, so you have some dedicated workers thoughout your environment.

After deployment change the second vmdk for the defaulted “small” configuration to approx 4GB plus (and Thick Eager). Why? Because the small amount of disk is used as disk test and fits in most storage cache. We need to get out of that and hit some real scenario’s.

One (or yes two) more things, logon to the consoles of all the appliances. Open a console, choose first option or press enter and login with root and password vmware. *ssst a very secret vmware user*. An other usage of the console is checking or monitoring the IOmeter tests i the console when they are running.


Type down one of the ip’s or hostnames of the appliances, and will use that one as the controller.

Open a browser (chrome or firefox) and type http:// and you will reach IO analyzer in your environment.

There we have the following options


For this I will use the workload configuration to add two tests to two appliances and check the results. Test scheduler is not used, will run immediately.

In this screen we first add the hosts where our test machines are, use the root password to connect to the hosts. When a connection is established the VM’s on that host are visible in the Add Workload Entry. Here you can find all kinds of IOmeter tests.


I have created two workloads, one Exchange 2007 on our first appliance and SQL 64K blocks on the other appliance. The duration is changed from the default 120 seconds to a 5 minute (300 seconds) schedule. This configuration is saved as Demo config.

Click on Run Now to let the test run. After a initialization you can see the progress in the console of one of appliances.


After completion of the tests you can view the test results in View Test Results (so it is not just a clever name :)).

Here you can check the two tests and the different VM and host metrics saved from IOmeter and esxtop (if there are any, you will get as a bonus the metrics of other VM’s on the hosts). More detailed information about these metrics, see the following URL: https://communities.vmware.com/docs/DOC-9279. Duncan Epping also has a good article about esxtop metrics and more. Go see his site when waiting for the test to finish: http://www.yellow-bricks.com/esxtop/

Here see the results of our Demo tests (I’m not going over in detail in this post).


Enjoy stress testing.

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