Another benefit of virtualizing servers is that they are no longer tied to a hardware platform. This provides the ability to virtually expand or upgrade (upgrade) the hardware platform during operation without significant downtime (~ 1 second downtime). Also, a hardware problem does not result in longer downtime (assuming existing spare capacity) because the VPS can be restarted quickly on a different hardware.
The force driving server virtualization is similar to that which led to the development of time-sharing and multiprogramming in the past. Although the resources are still shared, as under the time-sharing model, virtualization provides a higher level of security, dependent on the type of virtualization used, as the individual virtual servers are mostly isolated from each other and may run their own full-fledged operating system which can be independently rebooted as a virtual instance.