Initramfs in linux 0 [Release OL5 to OL9] Oracle Cloud Infrastructure - Version N/A to N/A [Release 1. Normally all files are cached in memory by Linux. It contains essential files and drivers required to mount the actual root file system About initramfs The only purpose of an initramfs is to mount the root filesystem. 8. By default, the kernel initializes hardware using built-in drivers, mounts the specified root partition, and Apr 14, 2015 · Now I need to regenerate initramfs to use the new partitions I cloned from hdd to ssd. Each of these will be discussed separately below with the help of an imaginary tool which performs a frobnication of a lvm partition prior to mounting the root partition The Linux kernel provides a very special syscall intended for early userspace and handling the move from initramfs to your root disk device. Numerous famous distributions, like Ubuntu, are from Debian. This is the cpio (copy in and out) archive of the source file system, which is … Nov 14, 2025 · Understanding `initramfs` is key for system administrators, developers, and enthusiasts who want to optimize the boot process, troubleshoot issues, and customize their Ubuntu systems. An initramfs is a file system hierarchy made ot live in the RAM of the device by compressing it. (The directory linux-*/usr is devoted to generating this archive during the build. 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. Key… NAME ¶ initramfs-tools - an introduction to writing scripts for mkinitramfs DESCRIPTION ¶ initramfs-tools has one main script and two different sets of subscripts which will be used during different phases of execution. available inside /boot/initramfs-$(uname -r). How to ensure the changes are applied upon rebooting? The /etc/multipath. This allows to create a minimal system running directly from memory. Why use an initramfs An initramfs is typically used to May 16, 2012 · I am running an HP pavilion dv6000 dual boot win7 and Ubuntu 12. Both are commonly used to make preparations before the real root file system can be mounted. It is not always the problem and it will be shown in the same way after running exit. Nov 29, 2023 · In summary, while both initrd and initramfs serve the purpose of providing an initial root file system during the Linux boot process, initramfs is considered a more modern and flexible approach with better compression support and integration into the kernel. Mar 2, 2024 · When changing root filesystem form an initrd to a "real" root device, you have to switch the root device. Contents of initramfs: ---------------------- An initramfs archive is a complete self-contained root filesystem for Linux. Rebuild initramfs for the problematic kernel with dracut: Jun 22, 2015 · Almost all Linux desktop uses initramfs at least with default configuration including LMDE v2 and initramfs feature is kernel inbuilt. Oct 31, 2021 · The solution was simple: Boot with a kernel that works (press Esc to see available boot entries on startup). Debian follows the open source values of accessibility and transparency and consist only free software. The author did this to enable Intel vPro on a Minisforum MS-01. Jun 29, 2023 · In order to truly understand the intricacies of the Linux operating system, one must have a firm grasp of the concepts related to the boot process. 8_all NAME update-initramfs - generate an initramfs image SYNOPSIS update-initramfs {-c | -d | -u} [-k version] [-v] [-b directory] update-initramfs -h DESCRIPTION The update-initramfs script manages your initramfs images on your local box. Dec 13, 2023 · I am working on an embedded Linux system (kernel-5. Not to fear, here are the fixes. Overview In Linux, the initrd (initial RAM disk) and initramfs (initial RAM File System) commands are different methods we can use to load a temporary root file system to the RAM or system memory for successful booting. One crucial element in this process is the Initial RAM Filesystem, commonly known as `initramfs`. cpio pointing to the exact same CPIO as from the -initrd example. When the kernel boots, it extracts the filesystem image into RAM and runs an init script from there. Mar 10, 2020 · Remember that GRUB line also has this GRUB_CMDLINE_LINUX_DEFAULT="quiet splash", and the resume should be added to what's there now. Issue How to rebuild the initial ramdisk image in Red Hat Enterprise Linux How to rebuild initial ram disk image in Red Hat Enterprise Linux How to remake or recreate the initrd or initramfs The /etc/lvm/lvm. Unlike older tools like mkinitrd, dracut uses a Requirement to remove a module from initrd image in order to avoid it loading at boot time. May 31, 2025 · Fix the Linux Mint / Ubuntu initramfs boot issue after a kernel update. Sep 25, 2020 · Hello my friends. initramfs-tools is installed Jun 1, 2024 · I have the following setup: artix linux OS linux-hardened kernel “6. You must at least specify one of those The initramfs provides a minimal Linux environment that enables the execution of programs before the actual root file system is mounted. Howev Jun 10, 2016 · Having an initramfs makes sense on PC-style hardware with lots of hot-pluggable devices. If <kernel version> is omitted, then the version of the actual running kernel is used. ) Feb 27, 2024 · Building an initramfs ¶ There are several ways to create an initramfs Using an initramfs_list config file ¶ Here is a simple example of building an initramfs with a stand-alone application and some basic dev nodes as the only components in the rootfs using an initramfs_list conifg file and the Linux kernels gen_initramfs_list. Mar 25, 2025 · 1. XX for about 2 years. initrd and initramfs (from initial RAM file system) refer to two different methods of achieving this. Complete step-by-step guide with BIOS/SATA Dec 7, 2024 · The initramfs is a crucial part of the Linux boot process. more Aug 8, 2024 · I am working on an embedded Linux system (kernel-5. Could anybody suggest something else? Jan 17, 2024 · Create a minimal linux from scratch with initramfs and busybox. Apr 3, 2025 · Understanding initramfs What is initramfs? The initramfs is an initial root filesystem that is loaded into RAM by the bootloader (usually GRUB) and then by the Linux kernel before the real root filesystem is mounted. I'll give you details about initrd and initramfs next. After a reboot, the boot process drops to the BusyBox shell and I end up at the prompt: BusyBox v1. Native Command Queuing (NCQ) is an extension of the Serial ATA protocol allowing hard disk drives to internally optimize the order in which received read and write commands are executed. Then we bad block the disk. It is bundled into a single cpio archive and compressed with one of several compression algorithms. If you don't already understand what shared libraries, devices, and Jan 29, 2024 · In Linux, the initrd (initial RAM disk) and initramfs (initial RAM File System) are different methods we can use to load a temporary root file system to the RAM or system memory for successful About initramfs The only purpose of an initramfs is to mount the root filesystem. for Linux on PS4. Initramfs, or initrd, is used as the first root filesystem that a Linux machine has access t Ubuntu stuck at initramfs prompt? Learn how to fix boot errors, run fsck, repair filesystems, and recover your system using step-by-step. And that’s where we might get deliberately vague … Oct 10, 2019 · The iniramfs is like a small os which mount root file system and hand over control to systemd. almesberger @ epfl. conf and root file system resides on a logical volume. Oct 7, 2025 · Some Linux-based computer systems require an initramfs to boot properly. Learn syntax, options, examples, and troubleshooting for kernel updates and system maintenance. Use root or sudo user credential to run this command: In particular, to (re-)generate an initramfs image based on the preset provided by a kernel package, use the -p / --preset option followed by the preset to utilize. initramfs error sometime happens in Linux boot time. At boot time, the boot loader loads the kernel and the initramfs image into memory and starts the kernel. 10. To solve initramfs error, repair the filesystem using fsck command. At a first glance, it is only slightly different than a traditional initrd. The initramfs is a complete set of directories that you would find on a normal root filesystem. 24-hardened1-1-hardened” encrypted root partition (no lvm) unencrypted boot partition (GRUB installed) device is a USB stick n Nov 30, 2020 · If initramfs gets corrupted or deleted at this stage because of recent OS patching, updates, or other causes, then we face a kernel panic. 04. 136ubuntu6. If <image> is omitted or empty, then the default location /boot On Red Hat Enterprise Linux 6 systems, whenever a new kernel is installed using either the Yum, PackageKit, or RPM package manager, the Dracut utility is always called by the installation scripts to create an initramfs (initial RAM disk image). Oct 2, 2024 · Understanding “initramfs problem” in Debian Free and open-source, Debian is an operating system based on Linux that is well-known for its dependability, security, and community-driven development. The initramfs or "initial RAM filesystem" contains critical files and drivers that the Linux kernel needs to boot properly. Using initramfs is optional. The dracut emergency shell is an interactive mode that can be initiated while the initramfs is loaded. This guide covers the concepts of the initramfs as well as how to properly create and manage initramfs instances. Pages of data read from backing store (usually the block device the Sep 11, 2017 · On Linux, the initramfs is loaded into memory by the boot loader, not the kernel; the boot loader also loads the kernel, and tells it where the initramfs is, so that when the kernel boots, it can find the initramfs in memory and use it to boot the system. It contains the core modules needed to boot Linux. This RAM disk can then be mounted as the root file system and programs can be run from it. It is a temporary root filesystem that is loaded into memory at the early stages of the boot sequence. The initramfs stage occurs just before the root file system is mounted. 0 to Oracle Linux 9. NAME update-initramfs - generate an initramfs image SYNOPSIS update-initramfs {-c | -d | -u} [-k version] [-v] [-b directory] update-initramfs -h DESCRIPTION The update-initramfs script manages your initramfs images on your local box. Ideal for system admins looking to customize or troubleshoot boot processes. The both solutions seem to be typical troubleshooting methods in case of initramfs booting issues, but they didn't work for me. So, how does initramfs work internally? Is there any scripts executed to mount the root in linux? Using the initial RAM disk (initrd) ¶ Written 1996,2000 by Werner Almesberger <werner. gz Provided by: initramfs-tools_0. The contents of the ramdisk would be wiped on the next reboot or power-cycle. By providing the essential tools and drivers in memory, it ensures that the system can mount the root file system and continue the boot process. May 9, 2020 · My understanding is that the initrd/initramfs set up a file system in the RAM to help the kernel initialization. Both of these concepts are part of the procedure for mounting filesystems. 24), and I am trying to enable initramfs in my system. Fix Initramfs Problem - Kali Linux In this quick tutorial, i will demonstrate how you can fix the kali Linux initramfs boot error, which often occurred due to a corrupted file system. 7K subscribers Subscribe Apr 21, 2020 · This guide explains how to build and customize a root filesystem (rootfs) for Xilinx devices, including setup, configuration, and modification instructions. Follow simple BusyBox commands to resolve the prompt and restore normal startup. Sep 22, 2025 · Learn to extract, modify, and repackage initrd files in Linux. This temporary root filesystem contains the necessary drivers, tools, and scripts needed to mount the real root filesystem and continue the boot process. I tried running dracut --regenerate-all --force from rescue boot but it didn't help. Pages of data read from backing store (usually the block device the Aug 24, 2023 · Linux OS - Version Oracle Linux 6. Dec 7, 2018 · I am attempting to get initramfs working on an embedded linux device using buildroot and uboot. It is implemented using the ramfs VFS driver in the kernel. Environment Red Hat Enterprise Linux 6 Red Hat Enterprise Linux 5 Note: For RHEL7 and RHEL8, refer to How to extract the contents of initramfs image on RHEL7? Issue How do I unpack or uncompress, and then repack or re-compress, an initrd or initramfs boot image file? How do I modify the contents of an initrd or initramfs? How do I view an initrd or initramfs? Resolution First, create a The `sudo update-initramfs -u -k all` command is used to update the initramfs image on a Linux system. How to Generate an initramfs file using the Root File System in Linux In this article, we show how to generate an initramfs file using the root file system in linux. 0] Linux x86-64 Goal This document covers the following questions: How to rebuild the initial ramdisk image in Oracle Linux? How to remake the initrd or initramfs? How to recreate the initrd or With initramfs a cpio archive (like tar but simpler) is supplied and the kernel unpacks the archive into a tempfs file system. It contains kernel modules and initial scripts. Sep 7, 2007 · Q: I think I am missing some driver or my initial ramdisk is corrupted for running kernel how do I Rebuild the initial ramdisk image under Linux? A: You need ramdisk if you have added new hardware devices such as SCSI or FibreChannel controller to your server as the ramdisk contains the necessary modules (i. Aug 21, 2023 · As far as I know, initramfs is a temporary file system used during the initial stages of the Linux kernel boot process. Pages of data read from backing store (usually the block device the The bootloader loads both the kernel and the initramfs into memory and indicates as much on the kernel command line in the boot header. The initramfs image is a small, compressed file that contains the kernel and essential drivers that are needed to boot the system. […] Dec 17, 2024 · The lsinitrd command provides various options to view and manage the contents of initramfs images, offering detailed insights which can be invaluable for system administrators, developers, or anyone working with Linux-based systems. For example, for the linux package, use the command: # mkinitcpio -p linux To (re-)generate initramfs images based on all existing presets, use the -P / --allpresets switch. It is the successor of initrd. You will have to look at the u-boot documentation to know how it works but I assume similar. Some distributors also prefer to customize a single kernel image with task-specific initramfs images, without recompiling. Also need to check the GRUB_CMDLINE_LINUX="" line. It works by first mounting your root disk into a mountpoint in initramfs and then pivoting the root filesystem into it. By updating the Jan 9, 2025 · What is initramfs ? initramfs stands for initial RAM filesystem. Jul 23, 2024 · Applies to: Linux OS - Version Oracle Linux 5. Initrd :- Initial RAM Disk Initramfs :- Initial RAM Filesystem Introduction to Initrd and Initramfs 1. Mar 17, 2022 · Download the latest Linux distros, kernels, initramfs, etc. 24), and now I am trying to create the initramfs where there is an interactive shell. Dec 1, 2020 · What I've tried fruitlessly so far: Repair the boot with boot-repair from a Live CD. Mar 16, 2013 · A ramdisk merely refers to an in-memory disk image. Afterwards, a new root file system can be mounted from a different device. It is often a hassle to get the grub menu during boot, but normally Esc will raise it, when pressed at the right time Oct 17, 2005 · Ramfs, rootfs and initramfs October 17, 2005 Rob Landley <rob @ landley. It can become outdated and need recreating (regenerate -ing) with more current boot files and info. The default is premount, for further options and a comprehensive description refer to man initramfs-tools. To start our Linux OS, we need to have either initrd or Jun 3, 2018 · To make the boot process stop in the initramfs, you have to add break to the kernel line in grub. Aug 23, 2019 · NAME ¶ update-initramfs - generate an initramfs image SYNOPSIS ¶ update-initramfs {-c | -d | -u} [-k version] [-v] [-b directory] update-initramfs -h DESCRIPTION ¶ The update-initramfs script manages your initramfs images on your local box. For some users, the initramfs worth creating manually, even if only to understand how it works, and what is happening inside. This Image storage location can be the root file system itself, a boot image on an optical disc, on a small partition on a local disk (usually using ext4 or FAT file systems An initramfs is the root file system inside a Linux kernel to help boot the system. Jun 17, 2019 · Corruption of initramfs can be occur by many ways for example after patching CentOS 7 Linux OS or installing a buggy device driver in server you found CentOS 7 Linux server has become unbootable. net> What is ramfs? Ramfs is a very simple filesystem that exports Linux’s disk caching mechanisms (the page cache and dentry cache) as a dynamically resizable RAM-based filesystem. In simple terms, both initrd and initramfs refers to an early stage userspace root filesystem (aka rootfs) that will let you run a very minimal . Nov 14, 2025 · Understanding Ubuntu Initramfs is crucial for system administrators, developers, and enthusiasts who want to troubleshoot boot issues, customize the boot process, or optimize system performance. Edit sudo -H gedit /etc/default/grub Nov 14, 2025 · In the world of Linux, the boot process is a complex sequence of events that involves multiple components working in harmony to bring the system up and running. Nov 14, 2025 · In the Linux ecosystem, `initramfs` (Initial RAM Filesystem) plays a crucial role during the boot process. Then we fix the NCQ errors. 5 ( Aug 4, 2018 · Today we will look what in initrd image, initramfs in Linux and what are the differences between them. fsck At the initramfs prompt, type: fsck /dev/sda5 NCQ You have NCQ disk errors. Residing in the Random Access Memory (RAM) during the boot process, this temporary filesystem is pivotal to successfully booting modern Linux systems because it equips the kernel with access to vital drivers and tools required to mount the root filesystem. Mar 1, 2022 · Maybe, but it is worth confirming that busybox initramfs shell is because root's filesystem needs to be checked/repaired. Dec 27, 2023 · By running some commands from the initramfs prompt, you can check disk health, fix errors, and get Ubuntu booting again. Last night things started acting strangely The Linux kernel can be configured to run from RAM by using the initramfs feature. User programs live in filesystems, so the Linux kernel must find and mount the first (or "root") filesystem in order to boot successfully. 1. It plays a crucial role in the Linux boot process by providing a temporary root filesystem that is loaded into memory. 18. The idea is that there's a lot of initialisation magic done in the kernel that could be just as easily done in userspace. If we dig into the boot process more, then we encounter the Linux "chicken/egg problem. I have got following doubts; (1) Is the initrd/initramfs is setup by bootloader(eg: May 30, 2022 · How to boot properly, fix the boot loader? Why my initramfs-fallback have higher size than newly created? (use mkinitcpio instead update-initramfs on arch) -rw------- 1 root root 29MB Mei 30 06:49 About initramfs The only purpose of an initramfs is to mount the root filesystem. There are different stages and one can instruct to stop at a given stage. When using initramfs, a filesystem image is embedded into the kernel image. Sep 30, 2009 · This week, I’m not going to write a formal column so much as just free associate a bit regarding an exchange we had recently on the Kernel Newbies mailing list regarding the ideas of initrd and initramfs, and what they’re for and, most importantly, how they differ. " in this video we are trying to showing you the error in Linux in boot time. The initramfs on the other hand, is some kind of interim filesystem with no underlaying device, so the kernel doesn't need to switch any devices - just "jump" to one. you can check it at your bootloader (GRUB) menu or after booting, run cat /proc/cmdline if Mar 30, 2023 · An important step in the Linux start-up process is mounting all necessary filesystems, including the root. There are three modes the built-in initramfs archive. This blog post aims to provide a detailed exploration of `initramfs` in Ubuntu, covering fundamental concepts, usage methods, common practices, and best practices. Dracut is a tool that is used to manage the initramfs. About initramfs The only purpose of an initramfs is to mount the root filesystem. The kernel has 3 ways to find and mount the root filesystem: all required device and filesystem drivers can be compiled into the kernel, The kernel uses the root= kernel command line option and if present, the init= option is used to find the Aug 6, 2020 · This brief guide explains how to fix Busybox Initramfs error on Ubuntu. By comparing the setups, we can conclude the most fundamental properties of each: in the hard disk setup, QEMU loads bzImage into memory. While both tools are highly capable and can build functional initramfs', they may not meet all use cases. Sometimes, a Linux administrator might want to regenerate the initramfs, say if they want to blacklist a driver or include an out-of-band module. You might need to check for swap partition too. Jul 15, 2021 · initramfs / init ram fs / initial RAM filesystem is a static copy of files needed to initialize and boot the computer. `initramfs` plays a vital role in the early stages of the Linux boot process, providing a temporary root filesystem that the kernel can Jan 29, 2024 · Initramfs, short for Initial RAM File System, plays a crucial role in the boot process of Linux-based operating systems. sh script. When the system boots, the initramfs image is loaded into memory and used to mount the root filesystem and load the rest of the kernel modules. Initramfs boots any Linux OS and mounts the root filesystem. This article is about understanding how initramfs works, and shows how to package a root filesystem as an initramfs. Learn to customize initramfs for specific kernels and include files with configuration finesse. The user… Sep 5, 2019 · How to fix Linux Mint initramfs Prompt at Boot: Linux Mint initramfs prompt appears after booting computer. Rebuild my ramdisk with sudo update-initramfs -c -k $(uname -r). Feb 17, 2024 · Learn how to resolve the BusyBox Initramfs error on boot menu in Ubuntu, Mint, Debian & other Linux distributions. x kernel? Aug 30, 2019 · How can I update initramfs somewhat how it is described elsewhere for adding firmware? For a Debian 10 I get a command not found error. The content of this directory should only be manipulated using the tools provided with the OS. The kernel Feb 15, 2022 · Do you have "fallback initramfs" menu entry in bootloader? If yes, boot fallback and rebuild initramfs with Oct 17, 2005 · Ramfs, rootfs and initramfs ¶ October 17, 2005 Author: Rob Landley <rob @ landley. The kernel uses the initramfs as a temporary rootfs, and the initramfs will likewise include an init process that runs in the initramfs stage. Understanding Initramfs and its scripts is essential for system administrators and developers For an initramfs, there is a kernel "rootfs" which becomes the tmpfs that the initramfs is unpacked into (if the kernel loads an initramfs; if not, then the rootfs is simply the filesystem specified via the root= kernel boot parameter), but this interim rootfs should not be specified as the root= boot parameter (and there wouldn't be a way to Feb 4, 2025 · Let's get started with an introduction of what an initramfs is, and then get into more technical stuff. The previous Mar 5, 2025 · The issue can be caused by the mentioned modules: mptbase mptscsih mptspi Follow these steps to resolve the issue: First, you need to backup initramfs. These are concepts like GRUB, initramfs, and the When the Linux kernel boots the system, it must find and run the first user program, generally called "init". What is an initramfs The initramfs is a temporary filesystem image used to help the Linux Kernel mount the root filesystem and run the main Init system. You must at least specify one focal (8) update-initramfs. Jun 23, 2016 · Remember the initramfs file system is a RAM filesystem, so to fix anything you need to fix the compressed initramfs image and/or fix the root filesystem. Sep 13, 2019 · Creating Initramfs Initramfs, short for “initial RAM file system”, is the receiver of initrd (initial ramdisk). Explore the mkinitrd command in Linux, learn to create custom initramfs images, and troubleshoot kernel boot issues using practical examples. This temporary filesystem provides the tools needed to mount the final filesystem and start the real system. It makes use of the APT Oct 17, 2005 · Ramfs, rootfs and initramfs ¶ October 17, 2005 Author: Rob Landley <rob @ landley. Pages of data read from backing store (usually the block device the See full list on linuxconfig. Pages of data read from backing store (usually the block device the Sep 28, 2021 · 19 I know I'm almost two years late here, but considering this has no answers To turn off your system from the initramfs shell, run the poweroff command: (initramfs) poweroff To reboot, you can use the reboot command: (initramfs) reboot -f Note that you must pass the -f (force) switch to the reboot command, without it the system does not reboot. (initramfs) fsck /dev/sda2 -y This will check it and when it is completed you get "FILE SYSTEM WAS MODIFIED" then (initramfs) reboot if reboot command does not work Sep 13, 2019 · There are two initrd image available with RHEL 7. Also download the latest versions of DXVK, VKD3D and other Linux gaming essentials. e. So, first, what is initramfs? initramfs stands for initial RAM-based file system. The computer does not boot up properly and instead of going straight to the login screen Nov 11, 2021 · 2 for whom who get this error: (initramfs) blkid you are gonna see this I use kali linux so run checkdisk for its partition. org About initramfs The only purpose of an initramfs is to mount the root filesystem. Just use a kernel that supports the particular hardware configuration it is built for. Introduction: What is dracut? dracut is a powerful tool used in Fedora, RHEL, and other distributions to create and manage initramfs images—the initial RAM filesystem used during system boot. Mar 11, 2024 · In this article we’ll show how to solve problems that occur when a computer running Linux Ubuntu/Mint/Kali doesn’t boot or drops to a busybox prompt during the initramfs initialization. img while the other one is available inside the RHEL ISO DVD which is loaded at the initial stage of system boot up. To that end, initramfs is a temporary root filesystem that the kernel loads in RAM during boot time. Aug 2, 2023 · Linux boot process with Initrd or Initramfs The Image of this Initial ROOT File System (along with the kernel image) is required be stored somewhere accessible by the Linux bootloader or the boot firmware of the computer. Sep 24, 2024 · So when trying to boot to one of my Kali Machines, it went to initramfs (INITial RAM File System) which is basically part of the scheme for loading a temporary root file system in memory to be with_initramfs/bzImage is a kernel compiled with options identical to normal/bzImage, except for one: CONFIG_INITRAMFS_SOURCE=rootfs. In this Feb 10, 2024 · In this blog post, we compile a small Linux kernel, and we will create a minimal initramfs archive that contains the basic Linux command line tools. Mar 27, 2025 · This guide describes process of re-generating initramfs of Linux installation using chroot (for example, using a Live USB). It keeps track of the existing initramfs archives in /boot. Mar 10, 2025 · Here is the easiest method to fix the BusyBox Initramfs error on Ubuntu-based systems using the fsck command in just 4 steps. I've been a GNU/Linux user for some years now, I've been running Kubuntu 18. The third article in the series is about creating root file systems that take advantage of initramfs. The one which is created after kernel is installed on the root file system i. de> initrd provides the capability to load a RAM disk by the boot loader. md Feb 26, 2025 · The BusyBox initramfs error can be a little scary because you might think that all of your data is lost. 6 Linux kernel series. Such manpilations may be useful, for example, in case the system fails to boot after changing of disks, cryptsetup partitions, re-created partitions with changed UUIDs. net> What is ramfs? ¶ Ramfs is a very simple filesystem that exports Linux’s disk caching mechanisms (the page cache and dentry cache) as a dynamically resizable RAM-based filesystem. 6 kernel documentation for a 4. It serves as an initial root filesystem that is loaded into memory during the boot sequence, providing essential tools and drivers required to mount the actual root filesystem. I configured the kernel as follows, CONFIG_BLK_DEV_INITRD=y CONFIG_INITRAMFS_SOURCE="/ May 28, 2024 · I can only access grub> and initramfs> command prompts and the language is very different. And followed by a sudo update-grub and a sudo update-initramfs. I have been following the guides have have initramfs set up in the buildroot and kernel config. Nov 3, 2025 · initramfs is a root filesystem that is embedded into the kernel and loaded at an early stage of the boot process. In this blog post, we will delve into the fundamental concepts, usage methods, common practices, and best practices related to Ubuntu Initramfs. The primary purpose of `initramfs` is to provide the necessary drivers, tools, and scripts to mount the real root filesystem, which could be a local disk, a network-attached storage, or Oct 17, 2005 · Ramfs, rootfs and initramfs ¶ October 17, 2005 Author: Rob Landley <rob @ landley. When the file systems are mounted, control of the boot process is passed on to How to FIX initramfs Error on Kali Linux | BusyBox initramfs error [100% FIXED] HackHunt 65. New in this forum, but planning to participate and finally get some expertise in this. I love it and will keep using it forever. Show the contents of the initramfs image for the current kernel Code: Apr 15, 2025 · In Linux, the initrd (initial RAM disk) and initramfs (initial RAM File System) are different methods that can be used to load a temporary root file system to the RAM or system memory for successful booting. Pages of data read from backing store (usually the block device the DRACUT(8) dracut DRACUT(8) NAME dracut - low-level tool for generating an initramfs image SYNOPSIS dracut [OPTION] [<image> [<kernel version>]] DESCRIPTION Create an initramfs <image> for the kernel with the version <kernel version>. (well, up until today). Why are you looking at the 2. Initramfs' are loaded quite a bit sooner than initrd's are. 0 and later: Oracle Linux: How to Rebuild the "initramfs" with Multipath in Oracle Linux 6 and 7 Mar 18, 2024 · The initramfs serves as a temporary bridge between the kernel and the actual root filesystem. The /etc/fstab file contains filesystems that we want automatically loaded when the system starts. Sep 22, 2025 · Rebuild initramfs on Linux using Dracut. The rootfs is mainly based on busybox, and the initramfs This directory is home to files needed for AL2023 to boot such as the Linux kernel and initramfs. In some cases, a SAN disk may get labelled as "/dev/sda", before the local disk does. There are three modes of operation create, update or delete. conf and my root file system resides on a multipath device Last time, we covered why initramfs was created: because it saves memory, gives the user more control over the boot process, and simplifies the kernel's internal implementation. Both initrd and initramfs can be compressed with gzip (or similar) providing the option to decompress the chosen type is enabled in the Linux Kernel. The old initrd was always a separate file, while the initramfs archive is linked into the linux kernel image. /boot/efi (EFI System Partition) By default, bootable AL2023 images are configured with the EFI System partition being mounted at /boot/efi. This minimal Linux environment is loaded into memory by BIOS or UEFI routines and does not have specific hardware requirements other than sufficient memory. The initramfs takes care of mounting file systems (by loading the proper kernel modules and drivers) . Sep 10, 2021 · The “initramfs boot problem” on Ubuntu or Linux Mint is a situation when a computer does not boot up properly and instead of going straight to the login screen, drops you to the BusyBox shell with the initramfs command-line prompt. The key parts of initramfs are: CPIO archive, so no filesystems at Jun 26, 2023 · In Linux, the initrd (initial RAM disk) and initramfs (initial RAM File System) are different methods we can use to load a temporary root… Sep 12, 2020 · First we repair the disk with fsck. - min-linux. I've used the following procedure on an LUKS encrptyed Ubuntu system in order to resume a boot broken by a bad crypttab. In this comprehensive guide, I‘ll explain step-by-step how to start up and run Ubuntu after an initramfs failure. The closest is : Boot drops to a (initramfs) prompts/busybox but it doesn't answer my problem. It provides early userspace which can do things the kernel can't easily do by itself during the boot process. The rootfs is defined in the (grub) command line and in /etc/fstab. Feb 6, 2010 · initramfs is the solution introduced for the 2. Pages of data read from backing store (usually the block device the Aug 25, 2025 · Master the update-initramfs command in Linux to manage initial RAM filesystem. Initrd and/or initramfs is used to load temporary root file system into RAM or system memory hence its named like initial RAM Disk/FS. Some OS like Slitaz and many embedded system OS like OpenWRT do not use initramfs image, they skips the initramfs image during boot, by a kernel boot argument noinitrd. In this article we study about the steps to update and rebuild initrd available in the RHEL ISO DVD, to discover the vital role of initramfs in linux booting—like a well-designed floor, it's essential for a smooth, efficient operating system experience. Feb 22, 2025 · Both BusyBox and initramfs play a crucial role in ensuring that a Linux system can boot successfully and efficiently, especially in scenarios where resources are limited. Oct 17, 2005 · Ramfs, rootfs and initramfs ¶ October 17, 2005 Author: Rob Landley <rob @ landley. Pages of data read from backing store (usually the block device the filesystem is mounted Apr 8, 2019 · The Linux startup process goes through several stages before reaching the final graphical or multi-user target. On the other hand, it makes no sense to boot an embedded operating system using an initramfs. ch> and Hans Lermen <lermen @ fgan. The initramfs is loaded temporarily into memory during early startup before the actual root filesystem is mounted. Jun 6, 2023 · It takes a few simple steps to extract the initramfs files on your Linux system to view their contents so let's open terminal and execute Apr 5, 2025 · An initramfs (initial ram file system) is used to prepare Linux systems during boot before the init process starts. Jul 4, 2025 · Understanding how to use dracut is critical for kernel upgrades, troubleshooting boot issues, disk migration, encryption, and even kernel debugging. #initramfs #ubuntu #linux [Solved] How To Fix Busybox Initramfs Error on Ubuntu | Ubuntu Boot Problem | Initramfs Error Linux | The Easy Conceptsmore Nov 3, 2025 · Why make your own The initramfs can be automatically created with sys-kernel/dracut and sys-kernel/genkernel. oorehfk edxob ooyg efp txkdm npayun ldscoeh ysfb oqnv rqgok qukl dll eyeifgh amqyd lvztf