While most of us QGIS developers are GNU/Linux converts or Mac users, none of us really work on windows. Our userbase however is very much a different affair. Download statistics reveal that a great many of our users are (stuck?) on Windows. Offlist we have been discussing this situation and have decided to put more effort into quality control of the Windows version of QGIS.

We already have the chroot environment that allows the Windows version to be cross compiled under Linux. However it doesn't provide many options for debugging and testing under Windows. To address this we have decided to build a native windows build environment using Qt4/Windows and mingw. The idea is that we will a) document the whole process and b) make a ready to use c:\mingw archive with all the dependencies compiled in it so that potential developers can simply download QGIS sources and build under windows using our preconfigured mingw. Well this is the idea we have anyway....

Yesterday I reformatted my desktop pc and performed fresh installs of Windows XP and Ubuntu Dapper on it. I performed a basic setup of windows - adding all latest security patches and getting rid of as much junk as possible. Now I am ready to start creating my mingw environment and so on. I think its good to have a clean machine available for testing, and since I cant afford to buy VMWare Workstation, I came up with a cunning plan :-) Before doing anything further on the Windows installation I have created a partition image in Linux using the 'dd' command line tool:


sudo dd if=/dev/hda1 of=windows.base.install.backup.dd


My idea is that for testing I can just revert the whole partition back to its just installed state, and then test QGIS Windows installers and the QGIS Windows build environmnet / procedure on an unadulterated copy of Windows. So when I want to roll it back I'll just do this:


sudo dd if=windows.base.install.backup.dd of=/dev/hda1


I'm going to give it a dry run test a little later today..hopefully it will work well and I will easily be able to get back to a clean room development environment....

Update on dd

Ok so the procedure I tested above works very well - I've successfully created two images - one with an clean base OS install and one with qt4 + mingw etc dev tools installed. And I can swap between them by booting into linux and issuing the dd command as described above. There are a few disadvantages:

* Each image takes 11GB of space on my linux partition - I can bzip2 them but it will result in a long delay to extract the dd image when I want to re-image my windows partition.
* Swapping images takes a bit of time and rebooting

The advantage is that I get to run windows at native speed and with real (as opposed to virtual) hardware devices which probably presents a better test environment.

Update on VMWare

As a few people have mentioned, there is in fact a free VMWare server edition. Before I started writing the above blog post I did in fact look into VMWare but I really struggled to make head or tail of the product details on their site and it left me with with the impression that I needed to have the Payware Workstation edition to create my own os images.

I found some nice clear instructions for getting it set up here which I followed and I am now creating my first VMWare XP image as I write this.

There are two downsides to VMWare I can see:

* Its gonna be a bit slow on my machine
* It needed to compile its own kernel module so every time adept updates my kernel it will require tinkering to get vmware running again.

The big advantage is I get to live in linux all the time :-) I'll play around a bit with both approaches and see which ends up being more workable....