Which server is better, given the same performance and price?
VDS KVM Ferrum offers:
- 40 Gb SATA RAID10
- 2 GB ECC RAM
- 2.4 Ghz x 2 Xeon CPU
- Unlimited traffic
- 1 IP address
While VDS OVZ Ferrum also provides:
- 40 Gb SATA RAID10
- 2 GB ECC RAM
- 2.4 Ghz x 2 Xeon CPU
- Unlimited traffic
- 1 IP address
The quality of your server performance depends on neighboring nodes. Choosing KVM ensures that you have guaranteed resources, but limitations on customization and connectivity abroad.
On the other hand, OpenVZ provides great performance on empty nodes but overselling and full nodes may limit available resources, with some users potentially taking more than their share.
With both KVM and OpenVZ, resource-intensive neighbors can also impact internet speeds.
KVM virtualization provides a fully-functional virtual machine with dedicated RAM, processor core, and hard disk. On the other hand, OpenVZ virtualization relies on the parent machine, with all containers using the same Linux kernel.
Resource limits are more strict with KVM, while OpenVZ performance may vary based on neighboring containers. KVM offers consistent allocation of resources.
For clarification, VPS and VDS refer to the same thing.
The VDS KVM Ferrum and VDS OVZ Ferrum both offer the same hardware specs. The primary difference between the two, KVM and OVZ, is in the virtualization technology they use: KVM (Kernel-based Virtual Machine) and OVZ (OpenVZ).
KVM: This is considered a full virtualization solution. Each VPS runs its own kernel and OS, which allows for more flexibility in terms of what you can run on it. You can install any operating system, including custom kernels and operating systems.
OpenVZ: This is a container-based virtualization system for Linux. OpenVZ servers use a single kernel and so require less resources, leading to potentially better performance on heavily loaded systems. However, they have limitations in terms of customizability. You are limited to the Linux distributions that the host provides, and you can't modify the kernel.
Given these points:
If you want maximum flexibility – i.e., you need to use an unusual Linux distro, or you need to modify the system kernel, then KVM would be the superior choice.
If you only need to operate within the constraints of common Linux distros, and you want less overhead from your virtualization (which could potentially lead to higher performance, especially on heavily loaded systems), then OpenVZ could be the better choice.
When choosing a Virtual Private Server (VPS), there are many factors to consider beyond the raw server specs:
Usage and Specifics: As previously mentioned, your exact usage case for the VPS is also an important consideration. If you require the use of any specific applications or services, you need to ensure they will work on the type of virtualization you choose and have the necessary software support. KVM would have the edge here because of its ability to run virtually any OS or kernel.
Scalability: How easily can you upgrade your VPS if you ever need to? Both KVM and OVZ have scalability, but the methods vary. For KVM, you must power off the machine to scale your resources, while OVZ allows live scaling (increase or decrease resources while the VPS stays online).
Performance: While these two specific offerings have identical specs, it's possible that you might see slight differences in performance between KVM and OVZ, due to the different ways in which they manage system resources. OpenVZ, due to its shared kernel, can sometimes enable better performance for the same resources. Still, in practice, the differences are often minimal unless you're pushing the server to its limits.
Security: KVM traditionally might have an advantage when it comes to security, as each VPS operates in its own isolated environment, with its own kernel and operating system. This makes it much harder for one VPS to affect another. On the other hand, because OpenVZ VPSs share a kernel, an issue in one container may potentially affect others.
Networking: Some providers offer features like DDoS protection or private networking. Depending on what you're using your VPS for, these might be important considerations.
Support: The quality of the provider's customer service could also be an important factor. Be it KVM or OVZ, having good customer support can sometimes make all the difference when you're dealing with issues or need some technical help.
OS Level Virtualization vs Kernel Level Virtualization: OpenVZ uses OS level virtualization where the host and all containers share the same kernel, while KVM uses kernel level virtualization where each VPS operates its own kernel. The major implication here is regarding the boundary isolation. KVM provides higher security due to its isolative nature compared to OpenVZ - if an OpenVZ guest were to be compromised, the whole system could potentially be at risk.
Ease of Management: In most cases, both OpenVZ and KVM provide similar levels of ease when it comes to operating and managing the systems. However, some may argue that KVM provides a wider range of management tools that could be beneficial for more complex deployments or for those who prefer having multiple options for task execution.
Backup and Recovery: Both virtualization technologies offer ways to back up and recover data, but the methods may differ. For example, KVM's full hard drive virtualization might make it simpler to move and restore backups, whereas OpenVZ's container model might make backups quicker and more space-efficient.
Latency and Overhead: As for latency and computational overhead, OpenVZ may have a slight advantage due to the fact that it operates with a shared kernel and does not require the emulation of hardware. However, the real-world implications of this are often negligible unless your workloads are teetering on the limits of your VPS resources.
Migration from One Host to Another: Migration is generally easier with KVM as it allows migration between hosts even with non-uniform processors. With OpenVZ, the host CPUs must be of a similar type which can complicate migration between servers.
Hyperthreading and Overcommitment: OpenVZ allows for CPU overcommitment and supports hyperthreading, which can lead to better CPU performance in certain situations. KVM, on the other hand, does not support overcommitment.
Compatibility: KVM is now part of the Linux Kernel, so it has a wide range of support for various Linux Distros.
User Base and Community Support:
KVM is built into Linux, it's maintained by the community and has generally larger user base compared to OpenVZ. Therefore, there's a wider range of third-party tools and utilities available for managing and orchestrating KVM environments.
OpenVZ is also supported by a community base and it's quite specialized. So if you're running a workload that benefits from OpenVZ's architecture, you're likely to find niche knowledge and tools that benefit you.
2. Underlying Technology:
OpenVZ leverages a shared kernel with Direct Kernel Context Switching to provide its services. This reduces overhead as the hypervisor (OpenVZ) doesn't need to replicate certain tasks for each VPS. But it also limits the functionality and potential compatible software of each container.
KVM is a hypervisor that essentially turns the Linux Kernel into a Type-1 hypervisor. Compared to OpenVZ, KVM allows for every VPS to have its own kernel, which allows running of practically any OS that is compatible with the x86 architecture. Despite this, it may have slightly more overhead due to running of full kernels and their own isolated set of processes, rather than sharing kernals and allocating resources at a process level, like OpenVZ.
3. Market Presence:
OpenVZ has fewer hosting providers and is not as widespread as KVM in terms of adoption.
KVM, due to its flexibility and the fact that it is part of the Linux kernel, has a larger market presence. It's widely adopted by many companies, from small hosting providers to large-scale cloud providers like Google Cloud and AWS.
. Licensing and Costs:
Both KVM and OpenVZ are open-source and free to use, which means licensing costs don't need to be considered. However, the total cost may vary based on additional factors such as management tools or control panels like cPanel, Plesk, or others which may have associated costs.
The overall operational cost can also depend on resource consumption. Networks utilizing KVM could demand more system resources, raising hardware expenses, whereas OpenVZ's lean operating model can potentially reduce hardware costs.
2. Use Cases:
OpenVZ, due to its lightweight containerization model, is perfect for running a large number of similar applications or services that don't need a full isolated kernel or the ability to run different operating system versions.
KVM, due to its full virtualization and isolation, is better suited for situations where there is a need for diverse applications, varied operating systems, and strict security requirements.
3. Redundancy and Failover:
Since KVM allows for full virtual machine creation, it might be better poised for live migrations and failover strategies.
OpenVZ, even though it has a leaner structure, might not handle some failover strategies as efficiently due to its shared kernel approach.
4. Customizability:
With its shared kernel approach, OpenVZ limits customizability to the kernel the host is running. You won't be able to make changes at the kernel or deeper system level.
With its full virtualization model, KVM allows greater freedom to customize the kernel and operating system of every instance, making it more compatible with custom applications, firewall rules, etc.