 | Virtualization is one of the very few technologies that is a perfect "Go Green", it not only saves on electricity but also saves capital and operational cost for companies. Virtualization has already started transforming computing as we know it (at least as we used to know it). VMWare, the virtualization technology pioneer is bundling their hypervision software into servers, very soon all servers will be virtualization enabled by default. As more and more companies adopt virtualization, demand for virtualization skills from engineer to Admins will increase ( and we are already seeing it). |
How does a Systems/Network guy get started on this exciting technology? We posed this question and a few others to 3 people who have, I think, as much if not more hands-on experience with virtualization than anybody out there. First, a few words about our "Virtualization Experts".
Bob Plankers: A system administrator, system architect, and designer, Bob has over 20 years of technology experience spanning desktops to servers, storage and networks. Bob blogs as the
"Lone Sysadmin", a moniker he coined after the "Lone Gunmen" of X-files, and also because many Sys Admins are lonely, one person against a whole organization that doesn't understand what
they do or how valuable they are when they're doing a good job. Bob is of the firm opinion that technology is easy, its the people + technology that is hard.
Scott Lowe: A technical lead specializing in virtualization and virtualization technologies, Scott is the author of the number 2 ranked blog in the "Top 10 blogs that VMware administrators must read" list from VMware-Land. Scott is a contributor to SearchVMware.com, a VMware-focused website with technical articles, how-to's, tips, and news. He has also had a few articles published on SearchServerVirtualization.com.
Martin MacLeod: Martin is an expert in deploying new servers,
decommissioning old ones, server and data center migrations, blade
deployment VMWare and grid
projects. Martin is the author of Blade Watch,
a blog where he tracks blades and grids. His blog shines a bright light
on the "dark arts" and mystery that surrounds servers and data centers.
It is a repository of information that System Engineers and Admins need
to know.
Q. For a SysAdmin, what is the best way to get started in virtualization technology, what are the pre-requisite skills needed?
Bob: The best way for a system administrator to get started in virtualization is to just start doing it on a small scale. There are numerous free products out there intended as starting points, whether it's the Linux KVM project, Xen, or VMware Server, and getting those products running on older hardware isn't a huge project. Create a test virtual machine or two. Learn how to clone them. Put a web server on one virtual machine and use a performance testing tool, like ApacheBench (ab), to put some load on the system. Watch the system under load and learn how to find the bottlenecks. Fix them if you can. Do the same for two virtual machines and watch how they interact. Learn how to give one of them priority over the other. Get to know the technology before you start putting real workloads on the system, but then make a plan to do it for real.
The prerequisite skills you need to get into virtualization are the same fundamental skills you need as a system administrator. Technology is easy, in that you can always learn how to configure VMware ESX, how to build a SAN, or how to configure a switch. The tricky parts are being good at linear troubleshooting, so when you're having a problem you find and fix it rapidly. You need to be good at diagnosing performance problems in operating systems. You need to be good at communication, to be able to accurately convey ideas, concepts, problem reports, and resolutions to those around you that aren't going to know as much about virtualization as you, and will be jumping to incorrect conclusions about virtualization. On top of it all you need to have an eye towards efficient machine management. When it's really easy to create lots of virtual machines you'll suddenly find yourself with 200 of them. How are you going to manage those? Have you thought about the tools you need? Are you the type of admin that looks into the future and sees the challenges ahead and the tools you need, or the type that looks back and complains about how much work 200 virtual machines is?
Scott: Virtualization technology in and of itself is not terribly difficult to understand. I believe that any reasonably experienced sysadmin will be able to pick up virtualization technology as easily as any other technology. The difficult piece for many sysadmins will be understand the other technologies that are directly impacted by and involved in the use of virtualization; namely, security, storage, and networking. Sysadmins will need a greater understanding of these areas and how virtualization impacts these areas in order to be successful.
Martin: The best way to get into virtualization is to look at your field, unix/linux/windows and look at how people are using virtualization on that platform. To understand the concepts, the opportunities available and think about how you could apply these in your role, in your work place. For example if you?re a Sun Sys-Admin, what are the virtualization possibilities, what things would you consider in your set up and how would you go about it. Consider downloading the different virtualization tools and trying them, it can be a great way of understanding the technology and the concepts. The key skills are in knowledge of the platform, a degree of capacity planning/performance analysis, and an understanding of service delivery.
Q. Virtualization is a catch all word, that includes server, storage, file and application virtualization. What has been adopted the most and why. Why are some areas lagging in adoption?
Bob: I don't have market data but I suspect server virtualization is the hands-down winner for adoption. Why? Because it's easy and saves a lot of money, right away. Storage virtualization is nice but when it comes down to it the return on investment hasn't been as great, often due to licensing fees. That's changing, with especially with technologies like block-level deduplication, but it's got a long way to go.
Application virtualization is a neat concept, too, and along with desktop virtualization they're really starting to gain ground.
Scott: Server virtualization, as exemplified by VMware ESX, Citrix XenServer, Virtual Iron, and the open source Xen hypervisor, is the most commonly deployed form of virtualization, and it is what most people think of when you use the term "virtualization". If I had to rank the other areas in terms of adoption, I would list storage virtualization next; this is a technology that is seeing broader adoption and usage by a variety of vendors. File virtualization, application virtualization, and presentation virtualization are relatively newly-defined areas--although some have existed under previous names for quite some time--and it will take some time for users to understand what these things are and how they can help them achieve their business goals.
Martin: Virtualization covers many arenas, from the server, network, storage and application standpoints. The focus in recent times has been on virtualization of the server, whether we?re talking about the Windows, Linux or Unix servers, and for some has been to answer issues of data center space and power, of consolidation. Virtualization of the server is the first step, we in essence abstract the application from the hardware, that we need not be tied to one server model, one set of infrastructure. The next step is to further enable the infrastructure through virtualization of the network and the storage, enabling us to use the capacity we have more effectively and further enable what we can achieve with the infrastructure. What we ideally want to achieve though is virtualization of the application and the infrastructure, where I allocate workload to a layer which hosts the service, the compute resources I need, where the application resides and on what infrastructure it is powered on is dependent on the availability and the performance requirements of the application. We can think of application virtualization in terms of grid/hpc or cloud computing at the moment, but mixing grid with a virtual storage solution, where I might have the immediate application data on high performance storage systems, but my archive data, my logs stored on less expensive, less immediate storage ? linking the application with the storage requirements based on need.
Q. Is virtualization a vendor specific skill, a VMWare expert is a VMWare expert and is unqualified to work with XenSoure?
Bob: Most of the virtualization concepts are the same between products, but the implementations and management methods are completely different. Most businesses also pick one product to use everywhere, so the folks working with it become experts in that specific software. For example, I'm great with VMware. I know how to troubleshoot performance problems, I know the management interfaces very well. I'm less experienced with Xen, and what I can do in VMware in seconds often takes considerably more time on Xen. It's a practice problem, in that the more I use Xen the better I'll get, but very few of the techniques are common between the two.
Scott: Refer back to question #1. While some areas are vendor-specific, i.e., knowing how to configure VMotion is uniquely VMware-related. In addition, many of these solutions are architecturally quite different from one another. Other areas will be the same across all server virtualization solutions. The key, as mentioned earlier, is understanding how these server virtualization solutions will impact security, storage, and networking. Once a sysadmin has a good understanding of the impact of server virtualization on these related areas, he or she will be able to more easily assimilate other virtualization solutions as well.
Martin: I've been asked this question before and I have mixed feelings about it.
My ideal virtualization person would be vendor neutral as much as possible, they would be knowledgeable on Xen, on VMWare, Hyper-V, x-VM amongst others. Let me phrase it this way; if you?re qualified in Linux, in Microsoft or VMWare, you are qualified in that platform. As a Windows server guy therefore, I know the basics in Linux I know the commands for disk space, to tail the logs and see what?s going on, but I would not be the guy to call at 3 in the morning to ask why my Linux server had crash dumped.
At the same time there are commonalities between the virtual platforms. We seek to achieve the same goal. The best practices we adopt, the systems we deploy and the way we set things up might change on a per hypervisor basis. Even the way the hypervisor virtualizes the hardware might change but the end goal is the same. For that reason, I would suggest that being qualified in one virtualization product would be suitable to work in a role managing or deploying a different virtualization platform with the right research and possibly training. It?s all going to depend on the role, the project and the business or risk involved, as well as the way we do business, the rules within your organization.
Q. What is your prediction regarding where virtualization technology can take us?
Bob: Virtualization is simply just the addition of a layer of abstraction, whether you're abstracting an operating system from hardware, or storage from the servers. Once you have that layer of abstraction there are lots of possibilities for what you can do. VMware's VMotion and Storage VMotion technologies are a good example of things you could never do before. Beyond that, there are lots of opportunities to use that abstraction to solve other problems, like disaster recovery and business continuity, clustering, workload management, software development, etc. In storage we're seeing deduplication, thin provisioning, and other technologies emerge. It all revolves around money, though, as businesses only want to spend precisely what they have to in order to get the job done right. If you ask yourself "what is my IT budget paying for?" chances are the answer will be something you can use virtualization on.
Scott: There are others out there far smarter and far more involved in the evolution of virtualization technology than I am. For what it's worth, though, I think that full hardware virtualization, such as that provided by VMware ESX, VMware Server/Workstation, Hyper-V, XenServer, and others, will evolve in two directions. First, on the server virtualization side, the layer of abstraction created by the virtualization layer will continue to strengthen and expand. This virtualization layer will make it possible to mirror VMs (two VMs performing the same tasks on two different host systems in real time) and provide very detailed and granular snapshot/checkpoint functionality, for example. On the desktop virtualization side, however, this virtualization layer will continue to get "holes" poked in it to streamline operations. This is typified by technologies such as Unity (found in VMware Fusion and in new betas of VMware Workstation 6.5), where the boundaries between the guest operating systems and the host operating system continue to blur and disappear. Thus, although these products are based on the same technologies, the ways in which they will evolve will be very different.
Martin: It?s an interesting one and a conversation I have regularly. I wonder if we will see the concept of a floating infrastructure. How cool would it be if my infrastructure followed the sun? Or even better the cooling/power costs? If I could have the infrastructure move to the data center with the lowest operating costs at that point of the day, if London could trade from New York, if Tokyo could be Moscow?s failover site rather than have a disaster recovery site? Where my infrastructure is not tied to a specific location?
Doing so would need a number of different technologies, and significant investment. We?re not there yet, but in a few years time with the cost of power going up, I wonder if the economic drivers might be there, do I really want my data center on 24/7 from a cost point of view? Could the 24/7 systems not move around to the data center that is on at that point in time?
One other thing is whether we will see a transition from Windows/Unix type roles to a more split type of guest and hypervisor support roles, I need guys that can support virtual machines (quite possibly cross platform) and guys that can support the hypervisor (again possibly cross platform). This is something I have mixed opinions about, we?ll have to see.
Q. What advice do you have for systems guys evaluating virtualization?
Bob: Set up a real test environment for yourself, so that you can learn the technologies without affecting real workloads. Go slow, and don't plan to virtualize your whole data center in a month. Don't plan to virtualize everything; some things don't make sense in a virtual environment. Be part of the user communities for your product, because they'll help you with tips and advice you won't get from the vendors. And finally, know what your goal is. Why are you virtualizing? To save money? To add cool features to your data center? To say you have virtualization? Knowing what your goal is helps you figure out what course to take.
Scott: Effectively embracing any form of virtualization--be it server virtualization, storage virtualization, I/O virtualization, whatever--involves abandoning old ways of thinking and understanding new ways of using this technology. Just because physical servers were provisioned a specific way in the past doesn't mean that virtual servers should be provisioned in the same way. The same could be said for configuring virtualized storage or allocating virtual I/O resources. Be willing to "think outside the box", or else you won't be able to take full advantage of virtualization in your environment.
Martin: When evaluating virtualization platforms, look at the licensing models, consider what is included, what the end user perception of the platform is, and remember that there is room for more than one virtualization platform. You might well have one platform for one operating system or application, and another for the mainstream, the shared infrastructure. Do download the different virtualization platforms and try them, speak with friends/colleagues and see what they are using.
A special thanks from me and OdinJobs to Bob, Scott and Martin for the insightful discussion.
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