Author Archive

Interacting With a chroot Environment

Thursday, July 15th, 2010
No Gravatar

Some services are capable of running in a chroot environment without having to build a separate chroot environment for them. OpenSSH and bind9 are both examples of chroot aware services. Simple config options will get you on your way to secure use of either of those. But for other services, like Apache2, things get more complicated.

It’s sometimes helpful to make a stand alone chroot environment so that you can run multiple versions of software. For example, it’s sometimes useful to run one version of php for your live server and experiment with upgrading to the newest php by running the newest php in a chroot. But how can you interact with the services running in the chroot?

IE6: The end is nigh update

Friday, May 28th, 2010
No Gravatar

Google recently launched a new site layout for it’s search results page. Google dropped official support for IE6 on March 1st, 2010. This meant that Google could rearrange the results page to be both mobile friendly (without switching to their mobile version, iPhone users rejoice!) and make the page much, much faster to render by the browser. In this day and age of fast, inexpensive computing, that might not look like much, but it’s still an advantage for mobile users, and lets face it, you’re probably still supporting Windows XP on your mom’s 6 year old computer, or trying to send links to your sister’s spam ridden and slow laptop, right?  The less time we’ve gotta spend chewing on a page load, the better for everyone.

How Canada’s Web Shop is green!

Thursday, April 22nd, 2010
No Gravatar

It’s Earth Day today, and that got me thinking about what we’re doing for the environment. Some of the things we do are for personal practicality, but it turns out some of those practices help the earth too!

Canada’s Web Shop uses network based services to share information and products between employees as a matter of speed and efficiency in our daily workflows, but the result of that is a nearly paperless office. It’s odd to find the printer out of paper, because we just don’t use much!

Internet Explorer 6: the end is nigh (hopefully)

Thursday, March 4th, 2010
No Gravatar

Have we seen the last of IE6? Google has dropped official support for Internet Explorer 6, and YouTube is close behind. It’s finally fallen behind Firefox in the web’s usage statistics. More and more developers are charging extra to add specs for IE6. Some people are even throwing funerals for the near-ancient browser (http://bit.ly/9ikjC1)!

No, we’re not out of the woods yet. Despite massive compatibility problems with the rest of the internet’s specifications, there’s still that last 20% hanging on, and it’s mostly for two quite understandable reasons.

Rebel Code

Friday, January 29th, 2010
No Gravatar

I was passed a very loved copy of Rebel Code by Glyn Moody. It’s about the beginnings of GNU, GPL liscensing, Linux, the Free Software Foundation, and the Open Source movement.

Running a completely different linux distro with chroot

Wednesday, October 21st, 2009
No Gravatar

The Linux chroot environments are often used to run pieces of software that are not compatable with the running distribution. For example, people running 64 bit Linux distributions will often create a 32 bit chroot environment based on that same distribution to run 32 bit software that might have better support. Adobe’s flash is a good example from the past: before 64 bit linux really gained popularity, only the 32 bit version of Adobe flash was available natively. But what if you need to install something that isn’t supported natively by your distribution at all, but is under a different distribution, and you’d like to keep package management the same?

Logrotate

Monday, September 21st, 2009
No Gravatar

Is the log for your custom app getting a little long? Have a need to keep your logs around but would like to keep their size down to a more managable size? Logrotate is the easy and powerful answer. You can tell logrotate to rotate your logs on various different triggers (daily, weekly, some other time, on a specific file size, on a specific number of lines, etc). You can tell it what to do before and after rotating (to put mysql into a safe state, or to restart apache to rebuild deleted log files, for example).

Expandable and fault tolerant filesystem

Tuesday, August 18th, 2009
No Gravatar

There are several problems with trying to create a large filesystem to store important data:

  • raid 5 isn’t expandable unless you find a harddrive that’s the same size as the others
  • LVM (Linux Volume Management) isn’t fault tolerant by itself, so if you lose one drive, your data is lost.

One of the best solutions I’ve found in dealing with these problems involves combining LVM with the Linux software RAID. You can cut up your collection of harddrives into common sized partitions, raid them together into several RAID5 collections (or even RAID1 collections), and LVM the resulting RAIDs.

VirtualBox as a development and testing tool

Monday, August 10th, 2009
No Gravatar

Sun’s VirtualBox package has been gaining steady ground on other virualization solutions in the areas of desktop os virtualization for some time now. Many have found VirtualBox 2 to be quite fast and snappy running Windows XP guest operating systems on Linux hosts. Version 3 was recently released that provided official support for things that they were previously experimenting with, like 3d acceleration for D3D and OpenGL applications on the guest OS. It’s even rumored to perform well playing games like Halflife 2.

Back to the basics, part 2: tar

Thursday, July 2nd, 2009
No Gravatar

One of the most common problems with tar is ending up with unexpected contents of directory structures in your tar archive (sometimes called a tarball).  I’ll show you how to create those nice, neat tarballs containing just the directory you wanted without the unnecessary preceding directory structure.