VMware Fundamentals Part 1

While this blog is designed to be specific to EMC VNX and VMware vSphere, I have decided to dig a little bit into the basics of VMware, how we manage it, how we work on it, and generally just how your daily life works in a VMware environment. Of course as always your mileage may vary, but this is to give those new to the product a little bit of confidence in what they just paid for, and hopefully to take some of the fear and mystery out of VMware. This originally started on my other blog, but I am going to be using this one more often, so part 1 is just a re-post.

Having worked with VMware since ESX version 2, sometimes I forget that not everyone speaks the lingo, and is obsessed with every feature of vSphere. This realization came when a client, whom I consider a good friend, asked me for some training on how high availability works, and how to vMotion a virtual server. In light of this I have realized the time has come to write a series on the fundamentals of VMware. This will be part 1 of many, I plan to continue to write until I run out of topics.

So to start with we need to look at the layout of vSphere. vSphere is configured in a hierarchical layout similar to the following.

Virtual Center or vCenter, controls the cluster. This may be a physical host, but more often than not it will be a virtual machine riding ontop of one of the hosts it manages. This allows it to take advantage of the high availability features in VMware. In our logical layout, this is the top level object in the virtualization hierarchy.
Next down is the virtual datacenter. This is simply a logical representation of the datacenter. Think of it similar to how you might have 1 or more datacenters within a corporation.
Next is the Cluster. This is a bit of a new concept in the IT world, we are used to clusters which might have a couple servers in it, but they are typically application specific. In the case of vSphere, we are actually grouping a number hosts physically together to create a pool of shared resources.
Under this we have the hosts and virtual machines. At a logical level these appear in the same level, they are both members of the cluster, but of course physically the virtual machine lives on one physical host or another. The virtual machine is nothing more than a series of files, a configuration file, a disk file, and a few others. This enables us to do some cool things like move the virtual server between hosts without interrupting normal operations.
So that about covers the basics, next I plan to cover vMotion, and then possibly get deeper into the networking layout and storage layouts. If you have specific questions, please feel free to reply to this thread.
VMware Fundamentals Part 1

Choosing the right product

Today I am going to write about something which a number of my customers are currently experiencing. Vendor selection, or rather technology selection, is critical. Choosing the right virtualization and storage solution is not so simple as it used to be. With the number of new technologies available to us, it is difficult to determine what is best. So how do you decide, and which products should you use to virtualize your environment.

To be fair, this is a blog about EMC and VMware products, but at the same time, I want to be clear, I am writing this as a consultant, with a fairly agnostic mindset, I just happen to like those products best in general.

So a client I am working on currently now, purchased an excellent backup solution. They are running vSphere, and are very happy with it, we are getting ready to move them to vSphere 5 from 4.1, and we are working to implement some best practice changes. Unfortunately, prior to our involvement, they bought a storage array from a vendor. The sales rep came in and told them what they needed without actually doing any design work, or looking at their environment. The performance was acceptable, but the Implementation, again done by the vendor, did not even follow their own best practices. When the client engaged us, we immediately looked at the issues, ran some tools to get a baseline, and made a list of recommendations.

As we have begun to implement the recommendations, we have found there are more issues which continue to arise. The storage is not properly designed for the I/O profile. The limitations on the vSphere design is creating a number of problems which we are having to work around. The network is was not properly configured, by the vendor who sold it to them.

So what is the point here, and how does this relate to EMC/VMware? I cannot emphasize enough the value of having a good consultant, even if you get the right vendor. Beyond that, understand your environment and be up front about it. Understanding your I/O patterns, your network load, your processing requirements are almost always the difference between a successful deployment and what we like to refer to as a Resume Updating Event. I am not saying if you hire me, or bring in EMC/VMware, everything will be perfect, I am saying rather make sure you have someone working on your environment you trust. Don’t ever trust a sales person, question them, make them explain all your questions. Factor in things like additional load from backups, look at your 5 year outlook, what might you implement in the future.

The landscape is changing, think about what vendor is going to be able to keep up with your needs, and what you are trying to accomplish. At the end of the day, no one ever got fired for asking questions of their vendors. If they can’t answer them and won’t get you answers, be very cautious about that vendor.

Choosing the right product

Phases of Virtualization

Often times we hear from our customers, about how they are approaching virtualization. Most of the people I talk to are somewhat virtualized, and often times, from an IT perspective they consider themselves to be fully or at least mostly virtualized. We have learned to ask, what does fully virtualized mean to you? This is the million dollar question. The typical response is something about everything that can be virtualized is virtualized. This is the question I would like to explore.

To lay the groundwork for this, there are about 5 common phases of virtualization.

Phase 1 is typically just setting up some test servers and virtualizing them with local storage using free software. This is the introductory phase.

Phase 2 typically involves moving the development or test environments, depending on the companies line of business, but these are non-IT test servers typically.

Once IT gets comfortable with this phase they are then ready to move on to Phase 3. This typically involves virtualizing the things IT has complete control over, domain controllers, maintenance and monitoring servers, and sometimes even email.

This is one of the most common places for what we have begun to term virtual stall. Getting the business to trust virtualization is typically a challenge. The concept sounds good, but the risks seem high. This is where it takes a good consultant to help bridge the gap between the technical team and the business units.

Phase 4 typically is where we begin to move business critical applications. This is where VMware on the VNX really begins to shine. While I really like competitive products, Netapp’s FAS line, Hitachi’s AMS, and some of the others, EMC has really helped us out here with not only by finally introducing unified storage, but by giving us the option for storage tiering and additional caching options. I plan to go into more details on this in a future post, but suffice it to say this is an incredible benefit for virtualizing mission critical high resource demanding apps.

Finally, the holy grail of virtualization. Phase 5 is IT-As-A-Service enables end users to generate their own servers through a simple web interface such as vCloud DIrector, or similar software. This is really where we want to get so IT can get back to playing World of Warcraft, or doing more behind the scenes work rather than always focusing on processing user requests.

This is a brief overview of the VMware/EMC “Journey to the Cloud”, but this is important for us to understand. Virtual Stall is a real problem, and should be addressed to prevent wasted money and resources. As budgets shrink, EMC and VMware continue to give us new and innovative solutions to make our business more agile.

Phases of Virtualization