Smoothwall Firewall project

Saturday 17 December 2011

The sad news of the death of Christopher Hitchens

The path to Atheism for most people on the planet is complex and fraught with a great deal of inner contemplation about the big issues that face us poor scared and frightened humans. It is with the help of great writers and thinkers that this process can be crystallized into your own detailed understanding and the ability to formulate your own view of these big questions.

Now, I can't say that Christopher Hitchens was the only or indeed main influence in my change of understanding. In fact he came very late to my party of transformation , which was far more deeply influenced initially by science and specifically the evolutionary writings of people like Darwin and Dawkins.

What he did bring once I discovered his work was a writer and essayist of such great conviction and clarity of thought, that it would be worth reading his work even if you were the most bigoted religious believer. The many articles and essays that covered an enormous array of topics and subjects. The realisation that this man was not just interested in a single topic , for which he has been grotesquely pidgin holed by some corners of the media, but was in fact deeply involved in many issues , of which religiosity was just one.

One thing I'm glad to say we had in common was our love of Evelyn Waugh, and thanks to his many books and essays on George Orwell, he has encouraged me to re-engage with a writer I loved when I was much younger. His insightful coverage of the many American presidential candidates and successful incumbents was always a delight to read. His characterisations of the current crop of extreme right wing religious Republican candidates was as humorous as it was salient.

I would also encourage others to seek out his many articles and essays from magazines like The Slate, Vanity Fair, The Statesman and The Atlantic to name but a few. Each one will question your beliefs and make you think about the topic being covered.

I certainly look forward to reading more of his works on Orwell, and I would suggest dear reader that it would be profitable to yourself to do the same.

Rest in peace Mr Hitchens, you will truly be missed.

Wednesday 7 December 2011

Issue with git client and Ubuntu 11.10 through corporate proxy

If like me you use git for storing code and configuration files, then it can become a problem when using it through a corporate proxy if you have the wrong versions.

I found today while trying to do a git clone the following error:

emote HEAD refers to nonexistent ref, unable to checkout

After searching around the web I came across this post.

This does indeed work.

Basically the problem is that the version of libcurl3 included with Ubuntu 11.10 has problem authenticating through a proxy. You either have to use 11.04 or upgrade your libcurl3 to the version in the next release of Ubuntu(precise), which fixes the issue.

I hope this saves you some effort.

This link also offers URL's to grab the latest deb packages to install, and more back ground on the issue.

Monday 5 December 2011

How to add another hard disk to your Xen virtual machine

If like me you have many Xen virtual machines that have been running for a while, you will likely come across the problem of having to increase the disk space, as the services or jobs the virtual machine offers over time changes.

Now you could increase the size of the existing disk, but I always feel that offers a level of risk, which with adding a new disk and using LVM or a new mount goes away.

Ok, so firstly we need to create a new virtual disk on the physical harddisk with the following command:

dd if=/dev/zero of=vm01-disk2.img bs=1G count=50

This will give us 50GB of new space. You can of course change the size to what ever you require, if your physical disk space will allow it.

Then we need to edit the Xen virtual machine configuration file and add in the new disk.

On my virtual machine host this is in /etc/xen/vm01

The line that needs to be altered is obviously the disk line, like so

disk = [ "tap:aio:/opt/xendisks/vm01.img,xvda,w",\
"tap:aio:/opt/xendisks/vm01-disk2.img,xvdb,w" ]

NB Notice the slash which allows the configuration line to expand over two lines in the configuration file.

Once you have done this, you can use the virsh and xm commands to restart the virtual machine , so that the new disk is available inside the virtual machine.

Once your VM has re-booted, you will notice another disk, which you can then either add to your LVM configuration, or just format and mount in a new directory. Here is my new mount as an example.

/dev/xvdb 50G 19G 29G 39% /opt/tomcat