What Are the Advantages of Paravirtualization?
One of the biggest advantages of paravirtualization is that it is typically more efficient than full virtualization because the hypervisor can closely manage and optimize resources between different operating systems. Users can manage the resources they consume on a granular basis.
“I’m not buying an hour of a server, I’m buying seconds of resource time,” Kalvar says. “The advantage of paravirtualization is that you get discrete resources as opposed to recreating a whole device.”
This approach is more efficient, according to Kalvar. “Rather than having a lot of idle resources that I’m paying for, I just pay for what I use,” he says. “I just pay for that moment, that instance, the memory, the compute that I actually use.”
Another benefit is in performance, because the guest operating systems for paravirtualization are specifically adapted or modified to run on the hypervisor. This design enables the guest operating system to make direct calls to the hypervisor’s application programming interface for, say, adapters, graphics processing units and other resources, Schulz says, which dramatically increases performance.
“The caveat is that the underlying hypervisor needs to support paravirtualization, as does the guest operating system,” he says.
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Full Virtualization vs. Paravirtualization
Full virtualization uses binary translation, and the guest operating system is completely isolated by the virtual machine from the virtualization layer and hardware.
“A key difference is that virtualization provides an abstraction to the guest operating system such that the guest can run it as is, without changes,” Schulz says.
Full virtualization lets users reserve full access to the processing, storage and networking capacity they need, Kalvar says. Paravirtualization provides much more granular control over those resources and when they are consumed. However, that requires having staff with the knowledge to manage those resources.
“You need to have the skills, and even more than the skills,” he says. “You’re also intensifying your operations load, right? That’s fine. That’s a trade-off. But that means you need to staff for that as well. It is an ongoing, intense effort that you have to make.”
Full virtualization also has more specific guardrails because all of the resources have been defined ahead of time, Kalvar say, meaning that resource usage cannot spiral out of control.
For example, there might be code that leads to a memory leak that is trying to consume the system’s RAM. “It gets up to wanting a terabyte of RAM,” he says. “The reality is, I only define the machine as having 64 gigabytes of RAM. So once it reaches that threshold, that’s it.”
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Cloud Computing vs. Paravirtualization
Cloud computing services can offer both fully virtualized and paravirtualized environments. In essence, virtualization and paravirtualization processes make cloud computing possible.
“Cloud computing is the on-demand delivery of computing resources over the internet with pay-as-you-go pricing,” AWS notes. “Instead of buying, owning, and maintaining a physical data center, you can access technology services, such as computing power, storage, and databases, as you need them from a cloud provider.”
Cloud service providers “create different virtual environments that use the underlying hardware resources,” AWS continues. “You can then program your system to access these cloud resources by using APIs. Your infrastructure needs can be met as a fully managed service.”
