Placing Legacy Applications in a Virtual Environment

Legacy applications can be encapsulated into executable packages that run completely isolated from each other in a virtual environment on data center servers. The virtualization layer maps the physical hardware resources to the virtual machine's resources, so each virtual machine has its own CPU, memory, disks, and I/O devices, and is the full equivalent of a standard x86 machine with Intel and AMD processors as well as with most Windows or Linux host operating systems.
In virtual operations the hardware support is provided by means of inheritance from the legacy host operating system.

Migrating individual applications to run on top of a hypervisor makes it possible to place different versions of the Windows or Linux operating systems to run conflict-free on the same server. Once the legacy applications are deployed in the virtual environment, individual application packages can be moved to different virtual computers, eliminating costly recoding and testing. After that the existing applications can migrate into successor environments in order to start conversion or conversion of previously disjointed or incompatible systems.

The placement of diverse legacy applications on a shared hypervisor offers the following advantages:

• Delivers uniform application access to all users.
• Eliminates the need for additional server hardware in support of different operating systems.
• Converts legacy applications for support by different operating systems versions without the need to recode, retest and recertify.
• Streams applications from a shared network drive with no intermediate servers or client software to install.
• Controls storage costs by providing a higher level of utilization.
• Allows over-allocation of storage capacity for increased storage utilization, enhanced application uptime, and simplifies storage capacity management.
• Lowers capital and operating expenditures by reducing disk purchase while reducing power and cooling cost.

SUMMARY

The encapsulation of legacy systems, with subsequent migration into a virtual environment is the next step after server consolidation. It should be seen as another phase of cloud formation.

The relocation of legacy applications into a virtual data center should be seen as an evolutionary step. It will deliver cost savings even after the legacy system will continue intact until such time when it is finally phased out.

The placement of legacy applications in a virtual data center should be seen as a way for aiming for the ultimate achievement of greater interoperability of data, communication links and application logic.