Ubuntu Unleashed 2013 Edition: Covering 12.10 and 13.04, Eighth Edition

Kernel

As the Linux kernel developed over time, developers sought a way to fine-tune some of the kernel parameters. Before sysctl, those parameters had to be changed in the kernel configuration, and then the kernel had to be recompiled.

The sysctl command can change some parameters of a running kernel. It does this through the /proc file system, which is a “virtual window” into the running kernel. Although it might appear that a group of directories and files exist under /proc, that is only a representation of parts of the kernel. When you’re the root user (or using the sudo command), you can read values from and write values to those “files,” referred to as variables. You can display a list of the variables as shown in the following. (An abbreviated ...