Open Source Disk Imaging

Disk imaging is used extensively within the IT departments of most companies. This enables them to quickly build desktops and laptops, to a repeatable standard and backup critical devices in order to quickly recover from a hard disk failure. In the past this has required some fairly expensive and proprietary software. These images are generally stored on a server but engineers can, and regularly do, carry a handful of them around with them.

The individual components required to do this with Open Source software do exist but until recently no-one seems to have tied them together with a nice, web based, front end. Enter FOG – a free open-source computer cloning system, which does exactly that. FOG is a Linux based server, that lets you backup and restore disk images for desktops/laptops and servers without the need to even carry a boot floppy/CD – as it uses PXE to boot from the network.

If setting this up sounds complicated, they do provide a VMWare virtual appliance for you to download use to do your initial testing – however, due to the large amounts of storage and IO demands, the VMWare appliance isn’t recommended for large scale production environments.

My initial tests are very encouraging and so if disk imaging is something that you are interested in, I wholeheartedly recommend checking this project out  – kudos to Chuck Syperski and Jian Zhang for creating this.


Art of Community

A good friend of mine, Jono Bacon, has just begun a new book. When he usually does this, I congratulate him and then give him a light hearted ribbing for having to use closed source software to write about Open Source topics. This time, as I was just getting ready to do so again, when he chirps in that it will be written in Free and Open Source Software – namely Open Office 3.0. Usually you have to be pretty dedicated to write a book without using proprietary software, you can either submit the book in in MS Word format or in Docbook format (like the Nmap book) but not this time apparently. Kudos to O’Reilly for this

Anyway, on to the book. Its called “The Art Of Community” and as Ubuntu Community manager I think he is pretty well qualified to write on the subject. The book will be available in two forms – a normal printed copy and it will also be available under the Creative Commons Attribution Non Commercial Share-alike license (for more see this site

I think its fair to say that Jono has a unique writing style and I for one cant wait to read it

Nice one Mr Bacon


Jono talks a little about using Open Source Software to write his book here

When Im 64(bit)

When I first got my home server, a few years back, I spec’d it with a 64bit processor. When I first installed the box I dropped a 64bit version of Linux on it. Pretty soon I realised that some of the additional software I wanted to run on it was not available in 64 bit, so I re-installed a 32 bit version of Linux on it and everything was fine.

The box does LOT of virtualisation both OpenVZ and VMware – with this in mind I recently decided to re-install the 64bit base OS on it and see if I could use some of the Virtualisation Technology thats built into CPUs these days. So this weekend, I backed up all the VMs and moved all the VEs to a different host while I re-installed the server.

It took the best part of a morning to get everything transferred back to the server and get the teething problems resolved. Once I got the VEs back, which was simple (vzmigrate rules), and copied the VMs back I decided to try and create my first 64bit VMware guest. This failed with the message “Your machine does not support long mode, use a 32bit OS”. Now if I wanted a 32bit guest I wouldn’t have gone through all this pain.

Google to the rescue – LOADS of people have had this error and its always been down to the same issue – VT being disabled in the BIOS. Upon checking this was also the case with my server. Im not sure why, when you have Virtualsation Technologies on the CPU, you chose to disable them by default but once I enabled it in the BIOS I was able to create 64bit Hosts (as well as 32bit hosts) on my new server. It (enabling VT) also seem to have brought my initially high load averages back down

To see if your CPU supports VT, if you run Linux, you can check your /proc/cpuinfo for the existence of either VMX or SVM. It will show up ever if its disabled in the CPU. Try this

egrep '(vmx|svm)' /proc/cpuinfo

The above tip was taken from this site

More info on VT can be found at the wonderful Wikipedia