A USB boot media can be created on any USB media device that is formatted as ext2, ext3, or VFAT format. Also, ensure that enough free space is available on the device, varying from 4 GB for transferring a distribution DVD image, 700 MB in case of a distribution CD image, or just 10 MB to transfer a minimal boot media image. Learning how to create a boot media will be beneficial for readers who are not very experienced with Linux.

Before starting the steps, you need to have an image file of a Linux installation disk, which you can name as boot.iso, and a USB storage device, as specified before.

Most of the Linux distributions include the kernel sources in them. However, these sources may tend to be a bit out of date. Because of this, you may need to get the latest sources when building or customizing the kernel.

Most of the Linux kernel developer community uses the Git tool for source code management. Even Ubuntu has integrated Git for its own Linux kernel source code, hence enabling the kernel developers to interact better with the community. You can install the Git package using the following command:

sudo apt-get install git

The need to configure the kernel could arise for many reasons. You may want to resize the kernel to run only the necessary services or you may have to patch it to support new hardware not supported earlier by the kernel. It could be a daunting task for any system administrator and in this section, you will see how you can configure and build the kernel.

It is always recommended you have ample space for kernels in the boot partition in any system. You should either choose the whole disk install option or set aside a minimum of 3 GB disk space for boot partition. Once you are done with the installation of your Linux distribution and have configured the required development packages...

After having spent a lot of time configuring and compiling the kernel, you can now start the process of installing the kernel to the local system.

Before starting with the installation of the kernel, make sure you back up all your important data on the system. Also make a copy of /boot/ onto external, storage which is formatted in the FAT32 filesystem. This will help repair the system if the installation process fails for any reason.

Once the kernel is compiled, you can start following the commands...

An important part of any open or closed software development cycle is testing and debugging. And the same applies to the Linux kernel. The end goal of testing and debugging is to ensure that the kernel is working in the same way as earlier, even after installing a new kernel source code.

One of the biggest issues with the Linux kernel is kernel panic. It is similar to the Blue Screen of Death for Microsoft Windows operating systems. If the kernel panics, it will dump a lot of information on the screen and just stay there. It is very difficult to trace a kernel panic if the system is rebooted as no logs are created for it. To solve this issue...

Sometimes your system might fail to boot due to changes within the kernel. Hence it is important that when creating reports about these failures, all the appropriate information about debugging is included. This will be useful for the kernel team in resolving the issue.

If you are trying to capture error messages that appear during boot, then it is better to boot the kernel with the quiet and splash options removed. This helps you see the messages, if any, that appear on the screen.

To edit boot option parameters, do the following:

1. Boot the machine.
2. During the BIOS screen, press the Shift key and hold it down. You should see the GRUB menu after the BIOS loads...

Kernel panic or kernel error is a term used when a Linux system has come to halt and seems unresponsive. When the kernel detects an abnormal situation, it voluntarily halts the system activity. When the Linux system detects an internal fatal error from which it cannot recover safely, it generates a kernel panic.

In Linux, a kernel error can be caused due to various reasons. Here we will discuss a few of the reasons:

• Hardware – Machine Check Exceptions: This type of kernel error is caused when a component failure is detected and reported by the hardware through an exception. This typically looks like this:

System hangs or kernel panics with MCE (Machine Check Exception) in /var...

Any operating system is as strong as its weakest link. In the case of Linux, any weakness in its kernel would imply a total compromise of the system. Hence it is necessary to check the security configuration of the Linux kernel.

In this topic, we will see how to use Lynis to check for kernel parameters automatically. Lynis has several predefined key pairs to look for in kernel configuration and accordingly provide advice.

To view or edit any security related parameter of Linux kernel, there is the /etc/sysctl.conf file. All the parameters are stored in this file and this is read during boot time. If you wish to see the available kernel parameters in this file, you can do...