It is not related to the Linux Virtual Server project, which implements network load balancing.
Linux-VServer is a jail mechanism in that it can be used to securely partition resources on a computer system (such as the file system, CPU time, network addresses and memory) in such a way that processes cannot mount a denial-of-service attack on anything outside their partition.
The contexts themselves are robust enough to boot many Linux distributions unmodified, including Debian and Fedora.
Virtual private servers are commonly used in web hosting services, where they are useful for segregating customer accounts, pooling resources and containing any potential security breaches.
The hard link is marked with a special filesystem attribute and when modified, is securely and transparently replaced with a real copy of the file.