Application virtualization can simplify virtual server management, so IT admins should educate themselves on the technology.
For those new to the concept, there are many parallels between server and application virtualization. Where the hypervisor abstracts the OS from the server hardware, application virtualization abstracts a program from the underlying operating system. And, as with server virtualization, there are various application virtualization methods and best practices.
Learning the nuances of application virtualization may take some time, but the payoff will ease server virtualization management. For instance, application virtualization can simplify the patching process and reduce the number of virtual machine templates that your organization needs.
The answers to these frequently asked questions cover the different types of application virtualization, what to consider when deploying the technology and how it will affect a virtualization admin’s job.
What are the types of application virtualization?
There are two flavors of application virtualization, and both approaches abstract the application from the underlying operating system.
- Remote apps/server-based computing: With this method, back-end servers run the virtualized applications, and the programs are streamed to a user’s device over a network connection.
- Client-based virtualization: The endpoint device runs the virtualized application. With this method, all of the files necessary to run an application are encapsulated into a single executable file. Unlike server-based computing, the application must use the client’s resources, such as CPU and memory.
Which application virtualization method is better: streaming or local mode?
It depends on the needs of your company and users, because both methods have their strengths and weaknesses.
The server-based computing approach allows for tighter security and easier management. All of the applications are centrally located in a data center, so you don’t have to worry about security breaches from lackadaisical end users who lose a computer. You can also stream virtualized application to non-Windows machines, which is great for running programs that don’t have native support for another operating system.
Client-based virtualization, on the other hand, allows users to run programs without a network connection. This method may also be better for resource-intensive applications that would benefit from running locally.
Which factors should I consider when deciding between the methods?
Your infrastructure will impact the decision to go with streaming or localized app virtualization. For instance, will the users have a persistent network connection? If not, server-based computing is out of the question. But, if the answer is yes, you can use either option.
If you’re interested in streaming virtualized applications, can your servers handle multiple, resource-intensive workloads? Server-based computing also needs a robust network with enough bandwidth to deliver virtualized applications.
If you’re sold on the client-based model, there are additional considerations. For example, do you want to use local agents to install and manage the virtualized applications? If so, Citrix Systems and Microsoft offer popular, agent-based tools. If that’s too much management overhead, you will probably lean toward VMware ThinApp.
How can application virtualization simplify management for server admins?
Application virtualization can potentially ease server virtualization management woes. In a virtual infrastructure, administrators must regularly negotiate application dependencies, the creation and management of numerous virtual machine images as well as the patching and updating of programs.
If implemented correctly, application virtualization can mitigate those difficulties. Because application virtualization encapsulates all of the necessary program files into a single package, dependency issues won’t arise. Administrators can also quickly move applications between servers and VMs without too much hassle.
It will also reduce the number of virtual machine images. Because the applications are encapsulated, you won’t need to tweak as many virtual machine templates to allow individual programs to run.
Finally, it’s generally easier to patch virtualized applications. Administrators can apply the changes to the virtualized application package and deploy them to the virtual machines.
Are there any pitfalls associated with application virtualization?
For all its wonders, application virtualization is not without its shortcomings. For starters, you can’t virtualize 16-bit applications, which may be a problem for some organizations that run legacy applications. But, as time passes and more legacy programs are naturally phased out, that restriction will become less of a stumbling block. You also can’t virtualize applications with kernel-based drivers, such as Adobe Acrobat.
Application virtualization also affects software licenses. For example, virtualizing Internet Explorer 6 is a violation of the Microsoft licensing agreement, because it’s technically a part of the Windows operating system. This distinction comes much to the dismay of organizations that built applications specifically for the IE6 browser.
Additionally, some applications licenses are tied to a hard disk serial number. Under those terms, streaming virtualized applications to various endpoint devices would violate the licensing agreement.
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