All right, so we already know in a nutshell what Wubi is about. But the real goal of Wubi is to help a new user get acquainted with the world of Linux, and Ubuntu is the best distribution for this task. It eliminates any of the “risk factors” by avoiding hard disk partitioning and/or formatting. Neither does it require expert skills to set up a boot loader to work along with your already-existing operating system. 

Therefore, Wubi was designed to do everything in a really short period of time. With today’s decent computers, the installation process doesn’t last more than 10 (ten) minutes. How’s that for installing another operating system? It’s pretty damn fast. And now you may ask, if it doesn’t partition your hard drive, where Ubuntu end up being installed? At the destination of your choice, Ubuntu becomes one large image file. 

This means that you can choose to install Ubuntu anywhere. It doesn’t matter as long as you have the necessary system requirements (most importantly, at least 5GB free space). The installation becomes a so-called “loopmounted device” that acts like a disk image. This is why it ends up as one really large file. As a side note, this means you cannot install it on a FAT32 partition, because large files aren’t supported—same as with DVD ISOs. 

Using this solution brings a lot of advantages and benefits, but also a few drawbacks. From your already-existing operating system, which is Microsoft Windows, you cannot access your Ubuntu installation (its a “disk drive” which is an image). Of course, from Ubuntu you will have access to all of your Windows files and folders, because those are physically to be found on the specific disk partition. 

Another small drawback is a minor worsening in disk I/O performance. This is because the operating system (Ubuntu) is in fact a loopmounted device, a disk image of the operating system, and therefore requires additional I/O disk access to maintain this format. But average users testing Ubuntu shouldn’t perceive any noticeable lag or other problems regarding performance. 

Now that we’re discussing the drawbacks, let’s also mention a few limitations that are widely discussed within the Ubuntu Forums community. The first one is that the Ubuntu that’s installed by Wubi is slightly more sensitive to hard reboots. It’s a file system that is in fact just a disk image file, so this can be understood. Hibernation isn’t supported either. Often, defragmenting the Windows partition may improve performance. 

However, after continuous test driving, if the user decides to remain on Ubuntu and to dedicate the required partition to the operating system, then this can be done without the necessary reinstallation. There’s an option called Loopmounted Virtual Partition Manager (LVPM) that allows users to install the Wubi-generated “disk image” file on a real, dedicated partition. This can be considered in the future once you’re convinced that you want to continue using Ubuntu. 

Another good thing that Wubi does automatically is create and maintain a boot-loader. It modifies the existing boot loader menu of your current Microsoft Windows installation and adds a new entry that launches Ubuntu, if need be. As soon as it boots up from that disk image file (c:\<path_of_your_choice>\disks\root.disk), the Linux operating system will see that as a real physical disk drive, and same goes for its swap partition, which in reality is just another disk image file (…\disks\swap.disk). 

On the next page we’re going to find out how to put Wubi into action.