Archive for the ‘ Scaling ’ Category

Paravirtualization With Xen On CentOS

Paravirtualization With Xen On CentOS 5.4 (x86_64) | HowtoForge – Linux Howtos and Tutorials.

This tutorial provides step-by-step instructions on how to install Xen (version 3.0.3) on a CentOS 5.4 (x86_64) system.

Xen lets you create guest operating systems (*nix operating systems like Linux and FreeBSD), so called “virtual machines” or domUs, under a host operating system (dom0). Using Xen you can separate your applications into different virtual machines that are totally independent from each other (e.g. a virtual machine for a mail server, a virtual machine for a high-traffic web site, another virtual machine that serves your customers’ web sites, a virtual machine for DNS, etc.), but still use the same hardware. This saves money, and what is even more important, it’s more secure. If the virtual machine of your DNS server gets hacked, it has no effect on your other virtual machines. Plus, you can move virtual machines from one Xen server to the next one.

I will use CentOS 5.4 (x86_64) for both the host OS (dom0) and the guest OS (domU).

This howto is meant as a practical guide; it does not cover the theoretical backgrounds. They are treated in a lot of other documents in the web.

This document comes without warranty of any kind! I want to say that this is not the only way of setting up such a system. There are many ways of achieving this goal but this is the way I take. I do not issue any guarantee that this will work for you!

The Coolest Server Names – Server Fault

The Coolest Server Names – Server Fault.

The funniest server name story I have is from when I worked at the Kennedy Space Center. On our particular project, our main server was named snowwhite, and the 7 client workstations were named after the Seven Dwarves. The kicker is, one day one of our engineers ran into a Disney Imagineer who worked at Walt Disney World, and they started talking about server names. The Disney Imagineer said “that’s funny, we have a group of servers named columbia, challenger, atlantis, and discovery.”



  • There’s a TONNE of them.
  • You’ll never run out of names.
  • They’re easy to Type:
  • Volcanoes are used for volatile servers
  • Long mountain names like KILIMANJARO are servers that you don’t want people to log onto
  • Different Mountain RAnges can serve as Clusters or a SAN. (The Rockies, Andes, Alps)
  • It’s always the user’s fault when they crash into a mountain
    • Mountains don’t crash
  • However, sometimes they explode (VESUVIUS)
  • You can rank them by Height and represent many of them pictorially in Network diagrams. (The Matterhorn, Mt. Fuji)
  • Mountains are great Security fortresses (Why do you think China wants to keep Tibet… it’s a plateau beside India!)
  • They are visible from outer space.
  • They can be classified in many different ways.
  • They can be Local (Intranet Servers) or in other countries/continents (WANs)
  • They are common to ALL people in all countries.
  • They can be named after people’s local hometown mountains. (When I was a kid I climbed to the peak of x mountain)


High Scalability – High Scalability – Google’s Colossus Makes Search Real-time by Dumping┬áMapReduce

High Scalability – High Scalability – Google’s Colossus Makes Search Real-time by Dumping MapReduce.

As the Kings of scaling, when Google changes its search infrastructure over to do something completely different, it’s news. In Google search index splits with MapReduce, an exclusive interview by Cade Metz with Eisar Lipkovitz, a senior director of engineering at Google, we learn a bit more of the secret scaling sauce behind Google Instant, Google’s new faster, real-time search system.