Читать книгу The Official (ISC)2 CCSP CBK Reference - Leslie Fife, Aaron Kraus - Страница 29

Virtualization allows the sharing of servers. Virtualization is not unique to cloud computing and can be used to share corporate resources among multiple process and services. For example, a service can have VMware installed and run a mail server on one virtual machine (VM) and a web server on another VM, both using the same physical hardware. This is resource sharing.

Cloud computing takes this idea and expands it beyond what most companies are capable of doing. The CSP shares resources among a large number of services and customers (also called tenants). Each tenant has full use of their environment without knowledge of the other tenants. This increases the efficient use of the resources significantly.

In addition, a CSP may have multiple locations. This allows services and data to move seamlessly between locations, improving resource use by the CSP. Services and data can easily be in multiple locations, improving business continuity and fault tolerance. The CSP can use the ease with which virtualization allows the movement of data and services to take advantage of available space and excess capacity, wherever it may be located.

This can create some security and compliance concerns, when data cannot move freely across borders or jurisdictional issues exist. These issues are best handled during contract negotiation. Another concern is if the hypervisor is compromised, as it controls all VMs on a machine. If the hypervisor is compromised, all data can be compromised. The security of the hypervisor is the responsibility of the CSP.