KVM stands for “Kernel-based Virtual Machine” which is a virtualization module baked into the Linux kernel. As long as the hardware has Intel VT or AMD-V enabled, it means the computer/computer server running the latest version of Linux can easily run one or more “full virtualization” virtual machines using KVM. Each virtual machine (VM) has it’s own private hardware, including networking, disk, and more.
- KVM is a full virtualization technology that uses hardware virtualization to create virtual machines. This means that each virtual machine has its own operating system, kernel, and resources, and can run any operating system that is compatible with the host hardware.
- KVM allows for complete isolation between virtual machines, as each virtual machine runs on its own kernel and has its own set of resources. This makes it ideal for hosting multiple applications or websites on the same server, as each application or website can run in its own virtual machine without interference from the others.
- KVM requires more resources than OpenVZ, as each virtual machine requires its own set of resources. This can make it more expensive to run KVM compared to OpenVZ.
OpenVZ only offers OS-level virtualization, meaning they use the host operating system’s (the host OS is the one running directly on the physical hardware) kernel. These are therefore a container-based system, and you may only run Linux operating systems on an OpenVZ container since it relies on the host kernel.
- OpenVZ is a container-based virtualization technology that uses the Linux kernel to create isolated containers for each virtual private server. Each container shares the same kernel and operating system as the host, but has its own set of resources and can be configured independently.
- OpenVZ allows for greater resource efficiency compared to KVM, as multiple containers can share the same kernel and operating system, reducing the overall resource usage. This makes it a more cost-effective option for hosting multiple applications or websites on the same server.
- OpenVZ does not provide the same level of isolation as KVM, as containers share the same kernel and operating system. This means that if one container is compromised, it could potentially affect the other containers on the same server.
Which one is better?
KVM is more versatile and will generally work better for your needs, as long as the VPS has enough resources. Go with OpenVZ if you have basic requirements on a VPS with low resource level provided (such as a small 128MB virtual server.)