The virtualization of computers in the laboratory is underway. The benefits of virtualization are well documented and those benefits apply to laboratory systems, too. However, those responsible for supporting these systems have questions about how virtualization will affect them.
The majority of the questions I have been asked can be distilled down to one, “Will my software run the same on a new virtual server as it does on my current physical server?” In other words, will making a server virtual alter the operational and performance testing required by the laboratory environment?
The simple answer is, “It should run the same.” Moving a software application from one server to another requires testing regardless of whether it is physical or virtual. However, simple answers come with conditions.
Condition 1: When moving an application from an existing server to a new physical server, a well-defined migration process should be employed. The process should include but not be limited to:
- The new hardware meets the minimum requirements specified by the software vendor
- The selected operating system is supported by the software vendor
- The hardware and OS will be configured to provide the functionality required by the software (network access, domain membership, user accounts, etc)
- Establish a test system on which to verify the data migration and software operation.
Assuming the above process is defined clearly, a formal migration of the current server to the new one could begin.
Condition 2: The primary requirement of a test system is that it is an accurate representation of the production system. If the test system doesn’t meet this basic requirement, issues related to hardware drivers, configuration options and performance may be missed during the testing.
In a completely physical server environment, the test and production servers should have an identical hardware configuration, including processor, memory, disk configuration and peripherals. With physical servers, this can be a challenge. Virtual servers, with their hardware having been virtualized, are much easier to “build” to be identical. With physical servers it is desirable to have the test and production servers from same manufacturer. Likewise, virtual servers should be running in the same virtualization host environment (VMware, Microsoft, Citrix).
Condition 3: Above the hardware, the configuration of the BIOS, operating system and patch level should be the same. These should be configured to provide the necessary functionality to access disk, network resources and other devices the software may require. Virtualization greatly simplifies this process, since when a VM is copied, these are duplicated precisely.
Condition 4: The new computing environment is robust enough to support the computing load that it will be used to support. Many times the move to a virtual server is prompted by performance issues and resource limitations of a physical server. Therefore, the new platform will need to have enhanced characteristics and resources to meet the demands that will be placed on it. Virtualization simplies the process of identifying needed resources. A VM’s resources can be increased or decreased to maximizing performance while ensure resources are optimally untilized.
In summary, the right question to ask when moving an application to a new server is “Will my software run the same on a new server as it does on my current server?” The best way to answer that question is by testing the application. In the end, it’s the application’s operation and performance that is essential to the business not the server’s physical or virtual incarnation.