PUBLIC MARKS from holyver with tags linux & server

Puppet, Chef, cfengine, and Bcfg2 are all players in the configuration management space. If you’re looking for Linux automation solutions, or server configuration management tools, the two technologies you’re most likely to come across are Puppet and Opscode Chef. They are broadly similar in architecture and solve the same kinds of problems. Puppet, from Reductive Labs, has been around longer, and has a large user base. Chef, from Opscode, has learned some of the lessons from Puppet’s development, and has a high-profile client: EngineYard.

Actually usually any web server can handle a normal day of work, but what happens when the server under your administration gets, stumbled, or appears in Slashdot, or digg front pages, now a days even twitter may drive a lot of traffic to a webpage.

This high-availability solution works by replicating a disk partition in a master/slave mode. The server that is running as a master has full read/write access to that partition; whereas the server running as slave has absolutely no access to the partition but silently replicates all changes made by the master server.

In this tutorial I will describe how to set up a highly available NFS server that can be used as storage solution for other high-availability services like, for example, a cluster of web servers that are being loadbalanced. If you have a web server cluster with two or more nodes that serve the same web site(s), than these nodes must access the same pool of data so that every node serves the same data, no matter if the loadbalancer directs the user to node 1 or node n. This can be achieved with an NFS share on an NFS server that all web server nodes (the NFS clients) can access.