Containment gives administrators a general-purpose undo capability. Administrators can suspend a virtual machine and resume it at any time, or checkpoint a virtual machine and roll it back to a previous execution state. With this capability, systems can more easily recover from crashes or configuration errors. See Recovery.
Containment also supports a very flexible mobility model. Users can copy a suspended virtual machine over a network or store and transport it on removable media. The hypervisor provides total mediation of all interactions between the virtual machine and underlying hardware, thus allowing strong isolation between virtual machines and supporting the multiplexing of many virtual machines on a single hardware platform. The hypervisor can consolidate several physical machines with low rates of utilization as virtual systems on a single computer, thereby lowering hardware costs and space requirements.
Strong isolation is also valuable for reliability and security. Applications that previously ran together on one machine can now be separated on different virtual machines. If one application experiences a fault, the other applications are isolated from this occurrence and will not be affected. Further, if a virtual machine is compromised, the incident is contained to only that compromised virtual machine.