dracut 是什么 - 重庆思庄Oracle、Redhat认证学习论坛

dracut is an event driven initramfs infrastructure. dracut (the tool) is used to create an initramfs image by copying tools and files from an installed system and combining it with the dracut framework, usually found in /usr/lib/dracut/modules.d.

Unlike existing initramfs's, dracut's framework attempts at having as little as possible hard-coded into the initramfs as possible. The initramfs has (basically) one purpose in life -- getting the rootfs mounted so that we can transition to the real rootfs. This is all driven off of device availability. Therefore, instead of scripts hard-coded to do various things, dracut's initramfs depends on udev to create symbolic links to device nodes and then when the rootfs's device node appears, it is mounted and root is switched to it. This helps to keep the time required in the initramfs as little as possible so that things like a 5 second boot aren't made impossible as a result of the very existence of an initramfs.

Most of the initramfs generation functionality in dracut is provided by a bunch of generator modules that are sourced by the main dracut tool to install specific functionality into the initramfs. They live in the modules subdirectory, and use functionality provided by dracut-functions to do their work.

Some people inside Red Hat started to name their projects after cities and villages around the developer headquarters of Red Hat in Westford, Massachusetts.