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Centos Virtual LAMP server -- Part II

*Part 1 of this series is here*

Customizing your LAMP server

Unix people are probably familiar with the father of the DNS system -- the /etc/hosts file. The hosts file has a simple format:

ipaddress hostname

In the days prior to DNS, people would update a master hosts file and copy it around to all the servers in the enterprise. Surprisingly Windows versions also support this file, as a way of overriding DNS, so we can use this to our advantage, by adding an entry for our development server. In this example, I'm going to use, which is not a real server.

One important reason to do this is that Apache and other web servers, use a feature of HTTP 1.1 that specifies a header field named "Host:". This mechanism facilitates the service of multiple domains from a single apache server, through the configuration of apache virtual host (or vhost) entires. The server uses the Host name in the HTTP header to determine how to route requests, so without host name resolution. you have to use non-standard ports and other mechanisms that are more trouble than they're worth. a

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Intel's T6500 -- No VT for you! Sony: You got Vaio VT? We turn it off.

At the time I'm writing this, you can easily find websites still listing the specifications for Intel's T6500 chip as including Intel VT. The T6500 is prevalent in the consumer Notebook space particularly because it was built to work with an 800mhz front side bus, allowing it to go in cheaper motherboards. You'll find the T6500 in a lot of midrange and budget 64bit notebook computers, from nearly all the major notebook manufacturers. Whether or not you care about VT depends on your interest in 64bit Virtualization software from Parallels to VMWare to Sun Virtualbox to Xen to VirtualPC.

VT is a marketing name for the hardware assisted virtualization workaround, originally named Vanderpool, that adds the Virtual Machine Extensions (VMX) instructions needed by VM's like Xen and Sun VirtualBox to provide 64bit OS virtualization. AMD has a similar set of extensions it added, marketed as AMD-V, although they built in the memory segmentation support that alleviates the problem with 64bit memory virtualization as far back as the D revisions of their AMD64 chips. One such website includes this boilerplate--

T6500 contain Advanced Technologies about Intel Virtualization Technology that increasing manageability, security, and flexibility in IT environments, virtualization technologies like hardware-assisted Intel Virtualization Technology (Intel® VT)

Click to see full size screenshot of original Intel specification.
If you were to have visited Intel's own site prior to July 20th of 2009, you would have found information indicating that the chip had VT support. This is a fairly mind boggling omission when you consider that the chip was manufactured, delivered to customers, and has been sold to customers for well over a month before Intel corrected its own site! On July 21st, Intel updated its website, and VT support is now removed from the specs. An Intel representative agreed that the information on the site was incorrect, once challenged by a consumer with a T6500 based machine, who had used Intel's own tools to enumerate the features on the chip.

I am sorry, I was mistaken. Thanks for bringing this to my attention.

The T6500 does not support VT. I used as my reference, but as you pointed out, the information turned out to be incorrect. The processor feature information for the T6500 contained within has been corrected. VT is actually not a feature of the T6500.

The processor identification tool is correctly reporting that VT is not a supported feature of the Intel® Core™2 Duo Processor T6500.

John S.
Intel Customer Support
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Run a Centos Lamp development server on XP, Vista or Win 7 using VirtualBox

If you use a Windows based workstation or notebook computer virtualization offers a way for you to run a linux server environment using the same linux distribution and configuration you'll use in production. Virtualization allows you to explore clustering and network setups that can't be tested on your workstation alone and simplifies your development environment by keeping the LAMP environment contained inside a VM.

While VMWare offers these capabilities with their VMWare workstation product, Sun has created a free alternative called VirtualBox, with many of the same capabilities in VMWare workstation. VirtualBox runs on a variety of intel chip based operating systems including OS/X, Windows XP & Vista, Linux and Solaris, and supports the installation of many different "Guest" operating systems. In this article, I'll detail the installation and configuration of Centos. Centos is a great choice for a Linux server operating system, as it is widely used by hosting companies due to its Redhat Enterprise Linux (RHEL) core.

Our goals in this setup will be:

• Centos server running the LAMP stack
• XP can be used to develop code using the IDE of your choice.
• The XP Workstation can communicate with the linux server using standard tools: putty, winscp, firefox
• The setup works even when no other networking is available. When a network is available, no network reconfiguration is required.
• Use XP to setup private domain resolution so apache vhost configurations can be tested.

Let's get started.

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Xen 3.0 Fedora Core, RHEL, Centos 4.x How-to

I gave a talk on the use of Xen for web developers at Lampsig. It took me a while to get my notes transcribed, but here at last they are. This prescription has been used by me to install Xen successfully on a Fedora core 4 box, Centos 4.3 and 4.4 boxes, and should probably work on RHEL, assuming you can figure out how to get the packages you need.

I cover use of file backed file systems, and how to mount and edit them, as well as expanding a file based filesystem.

I have run gentoo and Centos guests I got from and have found them to be very stable. I even was able to use this on a 64 bit server, although I did have to build my own guest. Many people who have had trouble getting Xen to work reliably when using the packaged (rpm) versions of Xen may find this prescription fixes their problems.

Xen 3.0 Centos How-to
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The 6 Million dollar site!

We can rebuild him. We have the technology.
We have the capability to make the world's first Bionic man.
Steve Austin will be that man. Better than he was before.
Better . . . stronger . . . faster.

After several web years having earned some sort of living from the development of interactive systems, I felt it was finally time to sit down and get started on a project that has been in the back of my mind for much of 2004. Namely, to relaunch, using database driven technology (in this case the popular LAMP combination [Gentoo Linux running as a UML instance on a coop server coowned and operated by myself and a bunch of people I met virtually through the Linux Users of Los Angeles, the Apache Web server, Mysql database server and PHP scripting language] as the platform for a php based "blogging" server called Serendipity. I realized some time ago that the original (which was always plain old html, created primarily in Dreamweaver) had always been designed to be a "Blog" of sorts, only I began it long before anyone had actually coined the term. Back in those days you just called it a homepage or personal home page. What I always wanted was a site that I could use as a repository for notes about my various projects, diary entries and musings about the places I've been, music I listen to, books I've read, movies I've seen, people I know, products I like and dislike, and things that I find interesting.

For quite some time the task of sitting down and manually updating things in the static html pages that comprised GizmoLA have made it an onerous task. The site has also moved a number of times and in the process things that were originally on the site broke or became obsolete.

I have a variety of goals for this new system, and I'm betting that Serendipity, which is still very much in Beta, will be the platform upon which I can build the type of site I have always wanted. As I work on converting the original Gizmola over, I'll try and elaborate on my goals, and provide an occasional update in the process.

My first order of business will be to convert some of the old articles over (or not, I haven't 100% decided how to proceed), and create a template that reflects as much of the original design as makes sense. This will certainly be an adventure in wrangling html and .css.

Another important aspect of what I want from my blog is the ability to include code and diagrams in certain blog entries. From what I can see this will probably be the first thing I'll need to create a module to do, unless I can find one that already exists. I did look hard at using the popular PHP blog package WordPress, even to the degree of installing it and adding in a few modules. I can't say for certain that my experience with Serendipity will be better, but the module architecture for Wordpress required me to do a lot of manual editing of existing scripts which didn't strike me as particularly modular.
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