Storage I/O Control (SIOC for short) has always been one of my favorite core storage features in vSphere. It was introduced way back in version 4.1, and has been instrumental in helping us address the pesky “noisy neighbor” virtual machine problem. These are virtual machines that from time to time generate a huge amount of I/O (for example, some data mining application), so much so that they impact all other virtual machines residing on the same datastore (increased latency). Storage I/O Control allows a vSphere administrator to put barriers around virtual machines to ensure that, even when an application running in a virtual machine requests a large amount of I/O resources, this demand can be contained via throttling of the I/O queue so it does not impact other virtual machines and application residing on that same datastore. If you are not yet using SIOC, and wish to learn more, here is an earlier myth busting article I wrote some time back.
One of the neat new features introduced more recently is the ability to reserve IOPS for a virtual machine, rather than simply placing a limit on it. So we are still actively working on improvements.
However we wish to make further enhancements, and we need your help to figure out what these enhancements should be. To that end, we have a very short survey (6 questions) to find out how you are currently using Storage I/O Control in your environments, if at all. Please take the survey by clicking here and help with the future direction of SIOC.