Virtual private server

In computing, virtual private servers are a means of splitting a single physical server into multiple virtual servers. Virtual private servers are sometimes called virtual dedicated servers. The practice of partitioning a single server so that it appeared as multiple servers was common practice in the days of mainframe computers, but has seen a resurgence lately with the development of software such as User-mode Linux and Xen.

Common applications

Virtual private servers have become popular in several different fields.

Perhaps most notable is the web hosting industry, where virtual private servers fill a void between virtual hosting and dedicated servers, allowing root-level access without requiring sole ownership of a server.

Virtual private servers have also become popular for their ability to establish sandboxes. For example, a single physical server might have two virtual private servers running: one hosting the production-level (live) website, and a second which houses a copy of it. When updates to crucial parts of software need to be made, they can be tested in the second VPS, allowing for detailed testing to be conducted without requiring several physical servers.

Virtual private servers are also sometimes employed to provide honeypots, allowing a machine to deliberately run software with known security flaws. Because it is possible to quickly deploy multiple virtual private servers on a single computer, honeypots are much easier to deploy, allowing better insight into the world of computer security.

Some commonly-used virtual private server platforms are as follows:

Xen

FreeVPS

Virtuozzo

OpenVZ

Linux VServer

OpenVPS

FreeBSD jails

Directory of VPS Web Hosting

Sphera Virtual Dedicated Server Technology