Different kernel versions between Ubuntu 12.04 and 12.04.3 (point release)

Ubuntu not only provides a very usable flavor of Linux, but a very easy to remember naming convention (try to remember for Windows). This blog is being authored from Ubuntu 12.04 (Precise Pangolin), where 12 corresponds to the year 2012 and 04 corresponds to the month April when that particular version of Ubuntu has been released.

Ubuntu releases a new version every 6 months. So, after the 12.04 release there had been 12.10, 13.04 and 13.10 releases. Every fourth releases (10.04, 12.04, 14.04 etc) is a LTS (Long Term Support) and is supported for 5 years, while the non LTS releases are supported for only 9 months. This is the reason for sticking to the Ubuntu 12.04 release, because it is supported for 5 years and there is no need to upgrade the OS again and again till 2017.

The main disadvantage of sticking to an old release is that within a particular release Ubuntu usually provides security/stability updates, but not any updates with new features. For example, Ubuntu 12.04 comes with R (2.14.1) while the latest is R (3.0.2). Software can be upgraded to the latest version in Ubuntu by adding repositories and installing the softwares.

Similar to Service Packs in Windows, Ubuntu also provides point releases.
According to Mark Shuttleworth :

These point releases will include support for new hardware as well as rolling up all the updates published in that series to date. So a fresh install of a point release will work on newer hardware and will also not require a big download of additional updates.

As some of you might noticed from the blog, I use Ubuntu a lot for trying out different things around Big Data and create Ubuntu Virtual Machines quite often as shown below. In-fact, I keep a copy of the pristine Ubuntu 12.04 image which will not only help to avoid the installation steps, but will also help in brining a Guest OS ASAP.

Recently on creating an Guest OS using Ubuntu 12.04.3 (note the point release), it was observed that there was a kernel version mismatch between the Host (Ubuntu 12.04 - 3.2.0-53-generic) and Guest (Ubuntu 12.04.3 - 3.8.0-34-generic) in-spite of doing an upgrade on both of them multiple times. The kernel version can be found out using the `uname -r` command.

Installing the VirtualBox the Guest Additions on the Guest not only provides a better performance in the Guest, but also a better integration (shared folders, full screen, shared clipboard etc) between the Host and the Guest OS. But, because the Guest OS was using an updated version of the kernel (3.8.0-34-generic), there were some conflicts because of which the Guest Additions were not getting installed.

After installing Ubuntu 12.04 (not the point release) as the Guest OS and updating the packages, the VirtualBox Guest Additions were installed properly. It looks like for better Hardware support Ubuntu point release come with a different or a more updated kernel as part of the LTS Enablement Stacks. More about this here.