A VPS (virtual private server) gives you the ability to host several instances of your operating system within a single dedicated server. Each virtual machine or container within your server behaves independently as though it were a server by itself. This gives users all of the benefits and administrative access of a full dedicated server without the high cost of maintaining actual server hardware.
There are many commercial virtualization options you can use to create a VPS system, but you should also consider these free and open source alternatives.
1. OpenVZ – A great alternative to Parallels Virtuozzo Containers, OpenVZ uses a container system to give your users root access to their own virtual private servers. In fact, Parallels Virtuozzo is based on OpenVZ, meaning the company has a financial interest in ensuring it continues to function well.
2. Linux VServer – With Linux VServer, you can run multiple “units” of your OS using kernel level isolation. They all still use the same kernel but are separate server instances from each other. In the project’s own words, it does this by using “”security contexts”, segmented routing, chroot, extended quotas and some other standard tools”.
3. Xen hypervisor – Although Xen is not exclusively designed for VPS management like the other two, many system administrators use it to create virtual private servers. Xen supports a wide range of operating systems and was developed by several large organizations, including Cisco, AMD, Intel, IBM, Citrix, and Red Hat.