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KVM vs OpenVZ
Understanding the differences between virtualization technologies
Table of Contents
Understanding Virtualization Types
KVM (Kernel-based Virtual Machine)
KVM is true virtualization where the VPS operates as its own server, independently of the host node. It has its own kernel and can run any operating system that the physical hardware supports.
OpenVZ
OpenVZ uses container-based virtualization, where the VPS shares the host node's kernel. This makes it more efficient but limits the operating systems to Linux distributions only.
Detailed Comparison
| Feature | KVM | OpenVZ |
|---|---|---|
| Virtualization Type | Full virtualization | Container-based |
| Kernel | Dedicated kernel per VPS | Shared kernel |
| Operating Systems | Linux, Windows, BSD, others | Linux only |
| Custom Kernel | Yes | No |
| Kernel Modules | Full control | Limited (requires host support) |
| Performance Overhead | Slightly higher | Minimal |
| Isolation | Complete isolation | Process-level isolation |
| Resource Efficiency | Moderate | High |
| TUN/TAP | Always available | Requires enabling |
| PPP/GRE/IPIP | Always available | Requires support request |
Which Should You Choose?
Choose KVM if you need:
- Windows or BSD operating systems
- Custom kernel compilation
- Full root access to all kernel features
- Complete isolation from other VPS
- Docker or other container platforms
- Complex networking setups
Choose OpenVZ if you:
- Only need Linux
- Want better value (more resources for the price)
- Run standard applications (web hosting, databases)
- Don't need kernel-level modifications
- Prefer higher performance for standard workloads
Current Recommendation
Cloud VPS (KVM-based)
RamNode now primarily offers Cloud VPS (KVM-based) which provides the flexibility of KVM with modern cloud features. Legacy OpenVZ plans are being phased out but remain available for existing customers.