The term “Virtualization” is commonly used within the IT industry the last couple of years.  Everything (hardware, operating systems, network, storage and application) is getting virtualized these days and organizations are ensuring to maximize their Return on Investment (ROI) to fulfill their ever growing IT requirements. Virtualization can be used to recover the system from disaster or avoid the disaster in the first place, if implemented correctly.

Evolution of Application Virtualization:

The application virtualization was present in the olden days with a different approach which was always hidden from that of the application functionality when interacting with the Operating System on which it was executed.  From Windows NT, INIFile mappings were introduced in order to virtualize the configuration reading operations to the legacy INI file (as if reading the configuration from registry) which was originally used in the Windows 3.1.  Similarly the latest virtual store feature (limited registry/file redirection feature) on Windows Vista and Windows 7 are known to support legacy applications and not write data to the system location (Root drives, HKLM registries etc) which was the case in the older version of Windows OS (XP and below), thus implementing the security in a much better way considering the older Windows OS.

Introduction to App Virtualization:

It is an Application Software technology that improves the application portability, manageability and compatibility there by encapsulating the application software’s completely from that of the underlying Operating System on which they are actually running.  In traditional application setup, the application components (registry and files) are installed locally on the machine but in case of application virtualization it is not the same.  It is just a single or multiple files stored within a single folder called as Virtualized Application files and usually executed under the process tree of its client part application code (MS App V Client, XenApp Client… etc) or even without any client code (ThinApp) which depends based on the vendor design.

Benefits of Application Virtualization:
1. No regression testing of applications

2. Reduce TCO and maximizes ROI

3. Ability to run multiple versions of the same application concurrently on the same machine

4. Eliminate conflicts among applications and with OS

5. Ease of Software Management (Upgrade/Migration etc) since it is not installed on the local machine

6. Better hardware utilization by the virtualized apps instead of using them in a separate VM

7. Application Deployment is accelerated and also the Application Streaming available on demand

Limitations of Application Virtualization:

1. Device drivers and 16 bit applications cannot be virtualized

2. Application size greater than 4GB cannot be virtualized

3. Machine based Licensing applications which depends on the machine specific unique identifiers (like Mac Address etc.) cannot be virtualized

4. MS Office Plug-ins are not suitable candidates for virtualization

The article has been contributed by HP