Paravirtueel

Paravirtueel is a term used in computing to describe a type of virtualization where the operating system is modified to run efficiently in a virtualized environment. Unlike full virtualization, which aims to emulate hardware completely, paravirtualization involves changes to the guest operating system's kernel. These modifications allow the guest OS to communicate directly with the hypervisor, bypassing much of the hardware emulation overhead. This direct communication is achieved through a mechanism known as a "paravirtualized interface" or "hypercall."

The primary advantage of paravirtualization is improved performance. By avoiding hardware emulation for certain operations, such as I/O requests, the guest OS can achieve speeds closer to that of a native operating system. This can be particularly beneficial for I/O-intensive workloads. However, the main drawback is that the guest operating system must be specifically designed or modified to support paravirtualization. This means that unmodified operating systems cannot run in a paravirtualized environment without significant changes.

Paravirtualization is often employed in scenarios where performance is critical, such as in cloud computing environments or high-performance computing clusters. It is a technique that complements other virtualization methods, and modern hypervisors often support a hybrid approach, utilizing paravirtualization for specific devices or operations while falling back to hardware emulation for others. Technologies like Xen and KVM have historically made significant use of paravirtualization techniques to enhance guest performance.