Subtitles of the Movie

The Special Issue: Kernel Updates. The Linux Kernel is at the core of the operating system. By some definitions, it is the operating system. Everything else that surrounds it are just a bunch of interpreters, consoles, and applications. The Linux Kernel enables communication with hardware. For some hardware, users have to configure, and even compile special drivers and that process is customized for a specific kernel version. One common example is the latest wireless cards. If the latest hardware doesn't work out of the box with the stock Fedora Kernel, developers often make the Source Code available which makes it possible to compile a driver for that kernel, but that gets tied to a specific kernel version. Similar factors are also at work for custom software. For example, the VMware server that I use for this course, when installed on Linux, has to be compiled with the tools associated with a specific Kernel version, so when I upgrade a kernel I end up having to recompile that VMware Server System using the updated tools associated with the newer kernel. These issues emphasize the importance of documentation. If you know the hardware with drivers that have been specially compiled for a certain kernel version, if you know the software that has been specially built with kernel version specific tools, then you can proceed with the kernel update. With this documentation in hand you can be fully up to speed with the amount of work that you need to do to make your hardware and software work with that updated kernel. But with that information in hand, some users may avoid a few kernel updates. When you update a kernel you just need to make sure you install and not upgrade, because an upgrade erases an installed kernel. An installation on the other hand, which fortunately is done by default with the update system tool, makes that kernel exist side-by-side with new and old. Those two kernels exist side-by-side, so even when you've taken all these precautions if something goes wrong you'll still be able to reboot in the original working kernel. To that end, let's review the boot configuration using the Boot Configuration Tool. To open that tool I click System, Administration, Boot Loader. I enter my root administrative password and it opens the Boot Loader Configuration Tool. In this tool you can review the configuration with an existing and a new kernel. You can set a different default kernel as well as a different time-out in seconds which can help you catch the GRUB menu from which you can select the original working kernel, or modify the commands given to that kernel. Well, those are the ins and outs of Kernel Upgrades.