KVM products are based on the so called KVM hypervisor and provide full hardware virtualization (sometimes called “bare metal virtualization”).
Almost every operating system (Linux dialects, FreeBSD, Microsoft Windows, …) can be hosted. Each KVM server provides 1 virtual CPU core @2.5 GHz. Compared to VRS products, the virtualization overhead is about 30% higher – that’s the reason why this product is slightly more expensive than VRS series products.
- TUN/TAP devices are available
- you are able to run every kind of networking services (VPN, …)
- Runs every kind of admin-panel like cPanel
- A second virtual NIC can be added
- KVM can be compared to a real hardware dedicated server.
- Operating systems can be installed at the touch of a button – you follow the installation (or interact with it) in a VNC session (similar to remote desktop).
- If the server is idle, the load is 0 (this is important for the comparison of the 2 technologies).
Comparing KVM and Linux vserver containers (VRS), VRS are no real servers, but hidden tasks in a large Linux mainframe. This kind of virtualization is called “context virtualization”. User feels driving a real speedy dedicated server – with minor limitations. Enjoy full root access to the server and install all the software you need.
Network resources are shared!
This means, that you have no access to TUN/TAP devices (no VPN possible) and iptables rules can only be added in a web-frontend. System load indicated is not the one of your VRS but the load of the Linux mainframe. pros: all available cpu cores (16/24/32) of the hosting systems are available to all VRS servers on a shared basis.
Operating systems can be installed at the touch of a button. Installation completes faster than on KVM.
Due to a much smaller virtualization footprint, VRS products are cheaper than their “big KVM brothers”.
OpenVZ (OVZ) is very similar to VRS containers, but comes with the following differences: TUN/TAP for VPN services can be enabled in the admin-tool. The load indicated in the VPS is the real load of the guest and not the one of the entire mainframe. Not all cpu cores are shared across the entire hostnode, but only 2 vcores (depending on the plan you picked).
OpenVZ plans are managed using solusVM control-panel. btw: OpenVZ is compatible with cPanel.
KVM and OVZ products can be used to
- bypass Great Chinese Firewall (Golden Shield Project, Red Firewall)
- unblock Facebook, newspapers and search engines in China or other countries with censorship
- bypass internet censorship