Virtualization is a technology that enables the creation of multiple virtual servers that run on a single physical server, sharing its resources, such as CPU, memory, disk, or network. The best approach to implement multiple servers on a virtual system is to implement one primary function per virtual server and apply individual security configuration for each virtual server. This approach can enhance the security, performance, and availability of the virtual servers, as it can isolate the functions and resources of each virtual server, prevent interference or conflicts between different functions, and allow for customized and granular security settings and controls for each virtual server. This approach can also facilitate the management, monitoring, and backup of the virtual servers, as it can simplify the identification, configuration, and recovery of each virtual server. References: Official (ISC)2 CISSP CBK Reference, Fifth Edition, Domain 3: Security Architecture and Engineering, pp. 507-508; CISSP All-in-One Exam Guide, Eighth Edition, Chapter 7: Security Architecture and Engineering, pp. 721-722.