I just read a great article written by James Knapp at ViFX (One of VMware's Premier Partners in New Zealand) on the Best Practices (and good practices) of utilizing a Management Cluster as part of your VMware vSphere architecture. I would recommend you read it. I'll give you my very brief take on this.
James' article is titled Best Practice for your Management Cluster. He outlines the reasons for having a Management Cluster as you start to grow you environment and as you start to utilize more technologies such as Virtual Desktop/End User Computing, vCloud Director, and Business Critical Applications, this will become even more important. One of the key points to consider is that having a Management Cluster doesn't mean you necessarily need more servers, as the Management Workloads will still consume the same amount of resources. But it can add considerably to the availability of your management systems and your availability and ability to manage your environment.
Separation of management infrastructure is not a new concept. It has been around for as long as I've been in IT (a little while). Traditionally your management functions, including authentication, would be separated off from all of the productive workloads, especially your network and security management systems. Going back a bit I remember that with Windows NT domain design we architected User Domains and Resource Domains. So the concept of management clusters and resource clusters for VMware vSphere should not be that foreign to those of us that have been in this game a while.
James nails the benefits and the separation considerations including storage. But the benefit that is often overlooked, especially by organizations that still insist on running vCenter installed on a physical / native OS (yes there are some). Having a management cluster gives you far higher availability, scalability and flexibility, without adding any costs, compared to the traditional approach. You also have far greater control over performance and quality of service with the latest advances in VMware Technology.
Even if your management cluster isn't a management cluster at all, but a single management host, you are still far better off having your management functions separated and virtualized to gain the benefits of hardware independence and quality of service. In a very small environment a single management vSphere Host may be enough, and this is easily scalable as your environment grows far larger. Granted this won't give you the benefits of high availability, but it's still better than having no management cluster at all, and you can easily add additional hosts as and when needed later. The important thing is to have the separation of resources in the first place.
I highly recommend everyone to have separation of management in their conceptual, logical and physical designs. It will make your job that much easier when things are going right and when they go wrong. This is also an important topic if you have any plans to sit the VMware VCAP exams or to become VCDX. It's just these types of considerations that will help you become successful, not just in exams and qualifications, but also in the real world. Thanks James for bringing up this important topic.
This post first appeared on the Long White Virtual Clouds blog at longwhiteclouds.com, by Michael Webster +. Copyright © 2013 – IT Solutions 2000 Ltd and Michael Webster +. All rights reserved. Not to be reproduced for commercial purposes without written permission.