Many IT environments of all sizes are enjoying virtualization in some capacity to save on costs, provision systems quicker and consolidate equipment. While the time to market availability for virtual systems is much quicker, there are built-in safeguards that can be rolled into any test, development or software quality effort.
All virtualization platforms offer some form of virtualized network functionality. I’ll talk about VMware’s ESX and vCenter Server, as it is the most popular in the space. A virtual switch is where virtual machines are connected to the network, and on the host side that virtual switch has a configuration as well. For test purposes, a fully isolated network can be provisioned for use by virtual machines on the host. Take the following example, an organization’s internal IT staff provisions a special virtual local area network (VLAN) to the host system, which is then configured as a port group in the virtual switch. At that point a virtual machine can be configured to access that VLAN for a private, testing only environment. The figure below shows an example of this configuration where four virtual machines are assigned to a private VLAN:
The private VLAN is not connected to the rest of the company network, yet the four virtual machines can communicate with each other. I like using the isolated virtual networks as they can be populated with other systems to test communications between virtual machines. Further, built-in virtual machine functionality of cloning and conversion allows copies of live systems to be put into the test environment quite easily. This example is not specific enough for many to take and use in their internal testing, but should be a springboard for conversation to see how network virtualization technology can be applied to your software testing and quality procedures.