What is a Virtual Appliance?
A virtual appliance is a software-based implementation of hardware appliances that provide specific application functionalities, designed to operate in virtual environments. Virtual appliances include an operating system, middleware, and application bundled into a virtual machine, making necessary application functionalities ready for immediate use when deployed in a virtual environment.
Recently, various network devices that were previously offered only as hardware appliances are now increasingly provided as virtual appliances. Factors driving this trend include significant advancements in the processing power of general-purpose servers, the widespread adoption of virtualization technologies, and rising demand for network virtualization. Unlike dedicated hardware appliances, virtual appliances run on general-purpose servers, reducing initial deployment costs. They are also easier to deploy, scale, or downsize as needed, simplifying operations. Additionally, through NFV (Network Function Virtualization), virtual appliances can help achieve SDN (Software-Defined Networking), allowing network configurations to be managed through software.
F5 offers its F5 BIG-IP, which implements Application Delivery Controller (ADC) functionalities, in the form of a virtual appliance called the Virtual Edition (VE). This VE version is also available for platforms like Microsoft Azure and Amazon Web Services (AWS).