Managing small virtual environments (Part 2) - Busting Myths

by [Published on 5 Feb. 2013 / Last Updated on 5 Feb. 2013]

In this, part 2 of this series, we’ll bust some virtualization myths.

If you would like to read the other parts in this article series please go to:

Introduction

Intended audience: If you’re a vExpert or have a certification that starts with the letter “V” then this article isn’t for you! Instead, please share it with your contacts in small and medium businesses that are either very lightly virtualized or have yet to do any virtualization.

In part 1 of this series, you learned about some of the basics behind virtualization and why even small organizations should consider either getting into virtualization or expanding their virtualization efforts. You also learned about how some common arguments against virtualization can be refuted.

In this, part 2 of this series, we’ll bust some virtualization myths.

Let’s start with the assumption that you’ve decided that virtualization is the right direction for your small business. Further, the focus here is on server virtualization. Desktop virtualization is a complexly separate discussion that will be considered later in this series.

Definitions

Here are some definitions that are important to understand before you continue reading:

  • Hypervisor. The hypervisor is the software layer that sits directly atop the server hardware. On top of this hypervisor layer, administrators install individual virtual machines. The abstraction provided by the hypervisor is the enabler for high-end workload management, including moving these virtual machines from one host to another. The virtual machines are not directly dependent on the underlying hardware, so they become portable between hosts.
  • Management tools. Management tools are components separate from the hypervisor that enable advanced management of the hypervisor and clusters of servers running the hypervisor.

Some myths: Busted (mostly)

When it comes to virtualization, there are truths and falsehoods, which, unchecked, can lead to poor or incorrect decisions being made or decisions being made for the wrong reasons. In this section, we’ll bust some basic myths about virtualization.

Busted: Virtualization is expensive

Virtualization alone is not generally expensive and, believe it or not, the cost is coming down as competition heats up in the market. There are some virtualization solutions available for free on the market while others carry a price tag.

For example, Microsoft makes their Hyper-V hypervisor available for free, while VMware charges for their vSphere hypervisor product. On the other hand, although Citrix does charge for their hypervisor (XenServer), they don’t charge for their management tools whereas both Microsoft (System Center 2012 Virtual Machine Manager) and VMware (vCenter) do.

 

Hypervisor

Management tools

VMware

Licensed per processor

Licensed per instance

Microsoft

Free

Licensed per processor

Citrix

Licensed per server

Free

Table 1

It should be noted that VMware does make available a free version of their ESXi hypervisor. While that product does provide very basic hypervisor capabilities, it does not include the capability to be managed with vCenter, nor does it enable advanced workload management techniques.

When it comes to management tools, particularly for small deployments, you don’t always need the management tools. Hyper-V servers, for example, can be managed quiet effectively without Virtual Machine Manager. Even without Virtual Machine Manager, you can carry out high-level tasks, including migrating a guest virtual machine from one host to another host. vSphere on the other hand, requires the use of vCenter in order to carry out these kinds of functions. In addition to enabling this functionality, though, vCenter also adds significant additional capability to the environment, including monitoring, license management, and much, much more. Because it’s such an integral part of the vSphere environment, vCenter will be covered more in depth later in this series. Further, we’ll cover the relationship between the hypervisor and the management tools later in this series, too.

Bear in mind that “expensive” is a very subjective term, too. For some, VMware’s solution is considered expensive because you have to buy both the hypervisor and the management tools. For others, Microsoft is expensive because of the perceived need to buy the full System Center 2012 suite. When we get to the licensing part of this series, you’ll be able to make a better judgment for your organization.

Busted: We need to buy high end hardware to leverage virtualization’s advanced features

There was a day when this myth was real; in order to use the advanced workload migration features found in the hypervisor, an organization had to spend the money and introduce the complexity of a shared storage system. The reason: All servers that were hosting virtual machines had to be able to see the same storage so that the virtual machine itself could be seamlessly transferred between hosts. Even then, some solutions weren’t as seamless as people wanted them to be. Then again, it was hard to live up to the ultimate workload migration tool: vSphere’s vMotion.

Today’s reality is a far different one. There are many companies now providing solutions that massively simplify the storage component in virtualization. Even VMware has gotten into the game with their Virtual Storage Appliance (VSA) product. Further, HP also recently lowered the price of and relaunched their own VSA product.

These products allow organizations to leverage easy-to-manage local storage. The various VSA products then transparently share this local storage between all of the hosts, thus enabling many of vSphere’s advanced workload management capabilities, including vMotion and Storage vMotion.

Local storage is generally less expensive and easier to manage than shared storage. You simply buy servers with plenty of disk space and then let the VSA tool work its magic.

This is just one example of ways that the market has responded to the need for decreased complexity and, in the process, helped to lower the cost of entry to virtualization.

Further, with the release of its latest version of Hyper-V, Microsoft is enabling a whole host of new possibilities when it comes to cost containment. When combined with the company’s new Server Message Block (SMB) 3 storage protocol, it becomes possible to deploy very inexpensive virtual environments that still retain very high level features.

Semi-busted: Virtualization creates licensing headaches

This myth is only partially busted because some companies—particularly one very large database company—find it necessary to treat virtual environments as somehow different than physical ones. This is generally nothing more than a cash grab, though.

With many mainstream applications, licensing in a virtualized environment has been a long-settled affair. In fact, in some ways, virtualization can make licensing easier. For example, for Windows environments, Microsoft has made it possible for companies to buy just one license per virtual host and then deploy as many copies of virtual machine-based Windows Server guests as possible on that host without incurring additional licensing fees. In cases like this, the myth is busted.

As mentioned, however, there are still companies out there that find it necessary to nickel and dime their customers to death. As such, before you jump into server virtualization, do a quick check with your software vendors to determine if virtualization will have a negative impact on your bottom line.

Busted: Virtualization makes it too hard to troubleshoot problems

When servers were all physically separate silos, when a problem arose, it was pretty easy to pinpoint what might be going on. From there, an administrator could then deep dive and solve the problem.

With virtualization, applications are all thrown into one big pot and mixed and stirred with the hoped-for outcome being that all applications continue to work as expected and get the resources that they need from the shared pool of resources.

It sounds like a messy thing to troubleshoot, doesn’t it?

Frankly, it can be. I will admit that it can take time to nail down exactly where a problem originates. Is the storage keeping up? Is the network overburdened? Is the host server experience a resource shortage preventing it from meeting the needs of all of the running workloads? Does the guest virtual machine have enough resources assigned to it?

Fortunately, there are dozens of companies out there that create monitoring tools specifically designed for virtual environments. These tools are relatively inexpensive and help administrators pinpoint exactly what’s going on in their virtual environments.

So, yes, virtualization can add complexity in some ways, but this is quickly negated when the right tools are deployed.

Busted: Most application vendors won’t support their product in a virtual environment

Another common concern revolves around application support in a virtual environment. In the early days of virtualization, many application vendors did refuse to support their products in a virtual environment. At the time, virtualization was a huge unknown. One of the most notorious companies in this regard was Microsoft, who used to make it all but impossible to get support for many of their products when they were running on VMware.

Today, for the most part, this concern is a thing of the past. Microsoft now supports their products in virtual environments, even when those products run on competing hypervisors. When there is a product that can’t run in a virtual machine or that has one component that can’t run in a virtual machine, that will generally be pointed out in the product’s documentation.

Although you should double-check to make sure that this isn’t a problem for your products, it’s very unlikely that your vendors will be so far behind the times!

Summary

Hopefully, understanding that many items that used to have some truth behind them have long been solved will help you as you make a decision about the future of your IT environment.

If you would like to read the other parts in this article series please go to:

The Author — Scott D. Lowe

Scott D. Lowe avatar

Scott has written thousands of articles and blog posts and has authored or coauthored three books, including Microsoft Press’ Exchange Server 2007 Administrators Companion and O’Reilly’s Home Networking: The Missing Manual. In 2012, Scott was also awarded VMware's prestigious vExpert designation for his contributions to the virtualization community.

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