You get an email from your boss. He's fresh from a conference, he's got all these new ideas, and now he wants to meet and talk about performance bottlenecks in the virtual infrastructure. He wants a report on all the bottlenecks and your plans to eliminate them in his inbox ASAP.
Now you have to explain in boss-speak what a performance bottleneck is, how "elimination" isn't exactly the term to use, and put together a report of your current bottlenecks and your plans to mitigate them. Excellent!
What Is a Bottleneck?
Bottlenecks in this instance are resources that constrain the performance of your virtual infrastructure. For example, say you have 90% of your hard drive free, but the system is still slow and you're only running the OS. In this case, assuming no other problems with the VM, memory is the performance bottleneck.
In the VM world, we're mostly concerned with memory, disk, and CPU bottlenecks. VMware performance monitoring is critical.
Symptoms of Bottlenecks
The most frequent sign of bottlenecks usually comes from users, unless you spend your day monitoring your virtual infrastructure. Unfortunately the symptom of bottlenecks from a user perspective is a slow VM. Obviously this could cover any number of issues.
If you take a look at the problematic VM, you should notice high activity in CPU, memory, or disk. If you use a management tool, look for high latency in those areas. High latency is probably the best indicator of a performance bottleneck from a VM management perspective.
Solving the Bottleneck Problem
In a long-term sense, you never really fix bottlenecks - you move them around. For example, let's say your current bottleneck is a memory issue. You added more memory and fix your performance bottleneck. But, six months later users are having the same complaint again. This time when you investigate, it seems that the disk is too slow for the demands of the newer OS and programs on the VMs.
Now you have a new performance bottleneck.
So, you can't "eliminate" bottlenecks, but you can prevent them.
If you use some virtualization management software, like SolarWinds Virtualization Manager, for your VMware monitoring, you can monitor your virtual infrastructure for performance bottlenecks and take preventative steps, or at least make a case to get the extra resources. Most tools even come with reports that will show you, and your boss, what is likely to be a bottleneck or is already a bottleneck. This makes everyone much happier in the long run