initrd

Initrd is a temporary file system that is used by the Linux kernel during the boot process.

" Initrd " stands for initial ramdisk ( loosely translated output partition in memory). The initrd is a reserved area in memory that is handled by the kernel, such as a hard disk partition (see RAM disk). It contains the image of a file system that contains the files needed to start the system. The initrd can be suspended by the Linux kernel and other Unix - related operating systems at boot as root. Then one on the existing program initrd (linuxrc ) is started. For embedded systems can be included in the initrd using all the functionality of the system. Personal computer using the initrd often meet only as an intermediate step to load drivers and other preparations for the start of the actual system. Through the initrd it was possible to make the boot process on Linux flexible and outsource functionality of the operating system kernel into userland.

To create initrd images, the program is usually used mkinitrd. Besides this, there are other alternatives such as yaird and Dracut. The Dracut project is now part of the kernel project.

Differences to initramfs

Initrd is deprecated and replaced by initramfs, which no longer has some weaknesses initrd:

• Initrd requires at least one compiled into the kernel file system driver.
• The initrd has a fixed size.
• All accesses to the initrd are again buffered in memory.