Picking the right virtualization for your VPS is actually a bigger deal than most people realize. It affects how your server performs, how stable it is, and whether you’ll run into limitations down the road. The two you’ll hear about most are KVM and OpenVZ, and while both work well, they’re completely different animals.
Clients ask us constantly which one’s better. The honest answer? It depends on what you’re doing. Let’s dig into how they compare.
What is Virtualization
Virtualization is basically how you take one physical server and carve it up into multiple virtual servers. Each one operates independently like it’s got the whole machine to itself, even though they’re sharing the hardware. A hypervisor manages the whole setup and keeps everything separated.
OpenVZ Explained
OpenVZ uses containers instead of full virtual machines. These containers share the host server’s kernel, which makes them incredibly lightweight. They all run on the same underlying operating system.
The key things about OpenVZ: it’s efficient, boots fast, uses minimal resources, and keeps costs down. The catch is you’re locked into Linux, and because resources are shared, some providers oversell capacity. You also can’t modify the kernel since you’re sharing it with everyone else.
For basic websites, simple applications, or anything that doesn’t need heavy customization, OpenVZ works great and saves you money.
What KVM Brings to the Table
KVM is full virtualization. Each virtual machine gets its own kernel, its own operating system, everything. It’s like having an actual dedicated server, just virtualized.
With KVM, you can run any operating system you want—Linux, Windows, BSD, whatever. Each VM is completely isolated from the others. You get guaranteed resources that don’t fluctuate based on other users. And you have total control to customize your kernel and install whatever you need. It’s heavier than OpenVZ, sure, but the performance is rock solid and predictable. If you’re running a business or need reliability, KVM’s where it’s at.
What Sets Them Apart
- Performance-wise, OpenVZ is faster for lightweight stuff because there’s less overhead. Everything shares one kernel, so it’s lean. But KVM gives you dedicated resources and consistent performance that doesn’t change when your neighbors get busy. For serious workloads, KVM wins.
- Operating systems? OpenVZ only does Linux. KVM runs anything. Need Windows? You’re using KVM.
- Customization is night and day. OpenVZ locks you out of kernel changes. KVM gives you complete access to configure things however you want.
- Resources are where it really matters. With OpenVZ, what you’re promised isn’t always what you get because of overselling. KVM allocates dedicated resources that are yours and yours alone. No surprises, no performance drops.
- Security follows the same pattern. OpenVZ containers share a kernel, so there’s some risk if something goes wrong at that level. KVM keeps each VM totally separate with its own kernel, giving you dedicated-server-level security.
When to Use Which
OpenVZ makes sense if you’re watching your budget, running something simple like a blog or small website, or just need a basic Linux environment. Students and people learning often start here because it’s affordable.
KVM is what you want for anything serious. Enterprise hosting, high-traffic sites, Windows servers, custom applications, VPN or game servers—anything where performance and reliability matter. If your project makes you money or serves customers, go KVM.
Why We Usually Recommend KVM
We offer both at Amaze Servers, but KVM has become the standard for good reasons. The performance is consistent, security’s stronger, you can run any OS, and it scales better. All the major cloud providers use KVM-based systems because it just works better for most use cases.
OpenVZ still has its place though. If all you need is cheap Linux hosting for something lightweight, it does the job fine.
What Most Hosting Companies Won’t Tell You
There’s something important that doesn’t get talked about enough in the VPS world, and it’s worth understanding before you commit to either technology.
A lot of budget OpenVZ providers will advertise packages that look amazing on paper. You’ll see plans with tons of RAM and CPU cores for prices that seem too good to be true. Here’s why they can do that: OpenVZ makes it really easy to oversell. Since containers share resources, providers can pack way more VPS accounts onto a single server than would ever be possible with KVM.
This works fine until it doesn’t. When your server neighbors start using their resources heavily, you might notice slowdowns. Your site loads slower during peak hours, database queries take longer, and suddenly that amazing deal doesn’t feel so amazing anymore. Not every OpenVZ host does this, but it’s common enough that you need to watch out for it.
With KVM, overselling is much harder to pull off. When you’re allocated 4GB of RAM, that memory is reserved for your VM and nobody else can touch it. The host can’t just promise the same RAM to five different customers and hope they don’t all use it at once. This is why KVM plans cost more, but it’s also why the performance stays consistent.
Another thing worth mentioning is how updates and kernel patches work. With OpenVZ, you’re at the mercy of your hosting provider for kernel updates. Since you share the host’s kernel, you can’t patch security vulnerabilities yourself. You have to wait for the host to update their kernel, which sometimes doesn’t happen as quickly as you’d like. We’ve seen situations where critical security patches took weeks to get applied because the host needed to schedule maintenance windows.
KVM gives you control over this. You manage your own kernel, so when security updates come out, you can apply them immediately. You’re not waiting on anyone else to protect your server.
The learning curve differs too. OpenVZ is straightforward because you’re basically working with a Linux container. It feels like a regular Linux server. KVM has a bit more complexity since you’re managing a full virtual machine, but that complexity comes with capabilities. You can snapshot your entire system, migrate to different hardware, and do things that just aren’t possible with containers.
For developers building applications that might need to scale, KVM makes more sense from the start. You won’t hit walls where suddenly your container environment can’t do what you need. Starting with KVM means fewer headaches down the road when your requirements change.
Making Your Decision
Here’s the simple version: KVM costs more but gives you real power, flexibility, and guaranteed performance. OpenVZ costs less but has limitations.
For serious projects, business use, or anything you’re building long-term, spend the extra money on KVM. You won’t regret having the headroom and reliability. For hobby projects, testing environments, or basic sites where budget’s the main concern, OpenVZ will get you going without breaking the bank. Whatever you choose with Amaze Servers, you’re getting solid hardware, support when you need it, and servers optimized to stay online.
