OpenVZ: Lightweight OS-Level Virtualization Solution
OpenVZ is a Linux container system that has been around for many years and is still remembered as the base for many VPS hosting platforms. Unlike hypervisors, it doesn’t emulate hardware. Instead, it splits one Linux server into many isolated environments that share the same kernel. Each environment behaves like a separate machine with its own processes, users, and network stack, but the footprint stays very small.
Core Characteristics
| Aspect | Details |
| Platform | Linux (patched kernels in classic OpenVZ; newer builds in Virtuozzo) |
| Virtualization | OS-level, single kernel for all containers |
| Features | VPS creation, resource limits, templates, live migration |
| Performance | Very close to native speed |
| Security | Process isolation, namespaces, cgroups, filesystem separation |
| Deployment | Requires Linux with OpenVZ kernel modules or Virtuozzo packages |
| Licensing | GPL (community), commercial support available through Virtuozzo |
| Audience | Hosting providers, labs, IT teams consolidating Linux workloads |
How It’s Used in Practice
Hosting providers built entire VPS businesses on OpenVZ because it allowed high density: one physical node could run hundreds of small containers. Each container felt like a real Linux system to the customer. In IT departments, OpenVZ was used for quick lab setups or to consolidate internal services where efficiency was more important than flexibility.
Deployment Notes
– Containers are created from prebuilt templates, so provisioning is fast.
– Resources can be tuned per container: CPU time, memory limits, disk I/O, and network bandwidth.
– Live migration lets administrators move running containers between servers with minimal interruption.
– Classic OpenVZ required patched kernels; newer Virtuozzo releases integrate with modern Linux versions.
Typical Scenarios
– A hosting company runs hundreds of customer VPS instances on each node.
– A research lab sets up isolated Linux environments for experiments or student projects.
– An enterprise IT team runs secondary services in containers to avoid wasting dedicated VMs.
Limitations
OpenVZ containers all share the same kernel. That means no Windows guests and no mismatched Linux kernels. Older releases also lagged behind the mainline kernel, which could complicate maintenance. While Virtuozzo has modernized parts of the platform, OpenVZ remains best suited for Linux-only workloads where efficiency is the main goal.
Quick Comparison
| Tool | Distinctive Strength | Best Fit |
| OpenVZ | Lightweight, high density | Linux VPS, hosting providers |
| KVM | Full virtualization, multi-OS | Mixed workloads, enterprise servers |
| LXC/LXD | Modern container system | Developers, cloud-native environments |
| VMware ESXi | Broad OS support, strong tooling | Enterprises with diverse infrastructure |

