What is initramfs and initrd?

From Wikipedia, the free encyclopedia. In Linux systems, initrd (initial ramdisk) is a scheme for loading a temporary root file system into memory, to be used as part of the Linux startup process. initrd and initramfs refer to two different methods of achieving this.

Is initramfs part of kernel?

– The old initrd was always a separate file, while the initramfs archive is linked into the linux kernel image. (The directory linux-*/usr is devoted to generating this archive during the build.)

What is initramfs used for?

Initramfs is used as the first root filesystem that your machine has access to. It is used for mounting the real rootfs which has all your data. The initramfs carries the modules needed for mounting your rootfs. But you could always compile your kernel to have these modules.

What is Vmlinuz and initrd?

The vmlinuz and initrd files are in a /boot directory. This directory is special — it is reserved for boot files, and the bootloader knows to look for this directory. It is generally a separate partition of the primary disk where the operating system is installed.

Is initrd necessary?

5 Answers. initrd/initramfs is optional and not a requirement. bzImage is the pure kernel image and can be booted directly by the bootloader.

What is initrd image and what is its function in the Linux booting process?

The Linux initial RAM disk (initrd) is a temporary root file system that is mounted during system boot to support the two-state boot process. The initrd contains various executables and drivers that permit the real root file system to be mounted, after which the initrd RAM disk is unmounted and its memory freed.

What is inside initrd?

The initrd contains various executables and drivers that permit the real root file system to be mounted, after which the initrd RAM disk is unmounted and its memory freed. In many embedded Linux systems, the initrd is the final root file system.

Why is initrd needed?

initrd provides the capability to load a RAM disk by the boot loader. This RAM disk can then be mounted as the root file system and programs can be run from it. Afterwards, a new root file system can be mounted from a different device.

What is the difference between initrd and Initramfs in Linux?

Both initrd and ramfs are zipped at compile time, but the difference is, initrd is a block device unpacked to be mounted by the kernel at booting, while ramfs is unpacked via cpio into memory.

What is initrd in Linux?

The initial RAM disk (initrd) is an initial root file system that is mounted prior to when the real root file system is available. The initrd is bound to the kernel and loaded as part of the kernel boot procedure. In the case of desktop or server Linux systems, the initrd is a transient file system.