From LQWiki

Contents 1 Linux Virtual Servers (LVS) for High Availability and Load Balancing 1.1 What an LVS is 1.1.1 Theory of Operation 1.2 Why you might want to use one 2 Alternatives to LVS 3 Additional Documentation

Linux Virtual Servers (LVS) for High Availability and Load Balancing

This page is going to be written. It will explain what a Linux Virtual Server (LVS) is, how it works, how to set one up, how to run it, how to take servers in and out of rotation.

What an LVS is

A Linux Virtual Server (LVS) is a linux machine with a special kernel and applications that connects together a group of physical servers (called a "farm") to form a single virtual machine that appears to the outside as a fast, reliable machine.

Theory of Operation

LVS works in one of three modes: Network Address Translation (NAT), Tunneling (TUN), or Direct Routing (DR).

	NAT	TUN	DR
theory	NAT theory	TUN theory	DR theory
Advantages	NAT Advantages	TUN Advantages	DR Advantages
Disadvantages	NAT disadvantages	TUN disadvantages	DR disadvantages

Why you might want to use one

There are two reasons you might want to use an LVS:

1. distribute a heavy load across multiple servers and
2. protection against the failure of a single server.

Alternatives to LVS

F5 BigIP

Additional Documentation

the LVS documentation http://www.linuxvirtualserver.org/Documents.html