Questions tagged [initramfs]

The "initial RAM file system" is the successor of initrd. It is a root filesystem that is embedded into the kernel and loaded early in the boot process.

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3answers
219k views

How to fix boot into initramfs prompt and “mount: can't read '/etc/fstab': No such file or directory” and “No init found”?

Installing a new system using a GPT partitioned disk dedicated to a single partition, ext4 formatted, extlinux (version 4.05) as bootloader, Ubuntu Core version 13.10 amd64 as rootfs, and Ubuntu linux-...
4
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2answers
1k views

pivot_root from initramfs to new root - error “Invalid argument”

You can not use pivot_root on an initramfs rootfs, you will get Invalid Argument. You can only pivot real filesystems. Indeed: Fedora Linux 28 - this uses the dracut initramfs. Boot into an ...
9
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2answers
6k views

extract Embedded initramfs

I have a kernel in which one initramfs is embedded. I want to extract it. I got the output x86 boot sector when I do file bzImage I have System.map file for this kernel image. Is there any way to ...
5
votes
1answer
2k views

unable to open luks encrypted device (wrong password)

I'm using CentOS 7 with a luks encrypted root partition. Usually I have to type my password during boot, but sometimes the system doesn't accept it. It reacts as it was wrong, but it isn't. I did not ...
2
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2answers
1k views

Understanding a simple configuration file for initramfs

Can somebody explain me what is happening in the following? # This is a very simple, default initramfs dir /dev 0755 0 0 nod /dev/console 0600 0 0 c 5 1 nod /dev/tty 0666 0 0 c 5 0 ...
15
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6answers
18k views

Why do I need initramfs ?

I found that if I choose jffs or sd as file system(and not initramfs),the kernel size is very small (1.4 MB as compared to with initramfs-3.4MB). It shows that initramfs takes concidreably large space....
17
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3answers
23k views

Does initramfs use /etc/fstab?

The way I understand it, initramfs is responsible for loading the "real" root filesystem. Now, there are two places where we define that root. First we put an entry in /etc/fstab. Second, we put the ...
10
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2answers
1k views

Difference in execution of init with embedded vs. external initramfs?

I'm building a very minimal Linux system that just consists of the kernel (v4.1-rc5) and an initramfs populated with busybox (v1.23.2). It works fine for the most part, but I observe a difference in ...
7
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3answers
7k views

How to generate initramfs image with busybox links?

Having been directed to initramfs by an answer to my earlier question (thanks!), I've been working on getting initramfs working. I can now boot the kernel and drop to a shell prompt, where I can ...
6
votes
1answer
13k views

Excluding kernel modules through /etc/modprobe.d/blacklist.conf does not work

I don't want to load the kernel module nouveau on my debian box at startup, so I put the following in /etc/modprobe.d/blacklist.conf: blacklist ttm blacklist drm blacklist nouveau I even did a ...
3
votes
1answer
2k views

Relative path to anything not working (while running from initramfs)

I'm working in an embedded Linux system trying to get it booting its root file system in ram using initramfs. The system comes up for the most part but then has trouble in the init scripts. I've ...
7
votes
2answers
637 views

Can initramfs be paged out to swap disk?

I am using initramfs to boot Centos via PXE. The initramfs used memory is listed within the "cached" value in /proc/meminfo or via free. Since I need to calculate performance data, I need to know ...
1
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2answers
2k views

Sudo apt-get remove python, gnome did not boot, tried dpkg --unpack *.deb

This happened after last night I was stubborn and sleepy enough to not read that it's best to install the missing dependencies from the var/logs and was lazy enough to just Google and try the first (...
18
votes
1answer
12k views

When would you use pivot_root over switch_root?

I'm wanting to understand the Linux init process better in order to netboot a system over ceph rather than nfs. In the process I've come across two forms of switching root. One called switch_root, ...
15
votes
1answer
20k views

What is the equivalent of mkinitcpio.conf on debian?

I want to review that the hooks used to build the initrd.img are correct in my debian but I fail to find the /etc/mkinitcpio.conf file like the one in Archlinux, what is the equivalent of this file in ...
5
votes
1answer
6k views

Adding a file to /etc of initramfs in Debian Wheezy

I have added the file /etc/initramfs-tools/etc/motd so that it would be available in /etc of the initramfs environment. However, it does not turn up. This is my second try where I gave the file all ...
3
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3answers
3k views

Why do we need initramfs and initrd

For example we have exotic file system on the disk and in order to load system we need mount root filesystem. But we cannot because there is no suitable driver exists in kernel image. Let me ...
2
votes
2answers
848 views

Why don't we include File System drivers in the kernel itself instead of using Initrd/Initramfs

The Linux kernel contains very minimal code that is necessary to boot on a majority of devices but I don't get the point of having Initrd/Initramfs.As far as I've understood Initrd/Initramfs job is to ...
6
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4answers
10k views

Unlock LUKS encrypted Debian root with key file on boot partition

I'm trying to decrypt the Debian root with a key file stored in the boot partition (decrypted partition). This will break the security, but it doesn't matter now. I have to conclude this successfully ...
8
votes
2answers
3k views

How is a Linux kernel capable of accessing its assigned initramfs/initrd?

I'm trying to understand the boot process of a machine as a whole from the time you hit the power button. There's this one piece from bootloader to initramfs stage I don't quite understand among some ...
6
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3answers
2k views

Is making /etc directory read only a bad idea?

I have an embedded system setup built using buildroot and using initramfs. It runs on compact flash device where I have created separate ext3 partitions to mount /etc/ and /var directories as well as ...
4
votes
1answer
11k views

After installing a new Kernel in Ubuntu 14.04, rebooting takes me to busybox initramfs. How do I mount a filesystem after that?

I have a virtual machine with Ubuntu 14.04 in it. I recently built and installed linux-3.14.5 kernel on it, and tried to boot into it, but it drops me to BusyBox v1.21.1 built-in shell. Here's what I ...
3
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2answers
2k views

Installing busybox for ubuntu

I'm trying to create an initramfs for ubuntu using this guide. How do I "re-create" the USE="static" emerge -av busyboxcommand on ubuntu, as emerge is gentoo-specific command? Basically, what are the ...
2
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2answers
3k views

Console setting in initramfs (ARM)

I'm in the process of porting the embedded system for a picozed-based platform from the Xilinx-v2013.4 (3.12 kernel) to the Xilinx-v2016.2 (4.4 kernel). The former version still makes use of an ...
2
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2answers
434 views

Why kernel cannot do the initrd/initramfs job itself? [closed]

Currently I am learning about linux booting process.Here i noticed that the initrd will create temporary root file system that includes drivers(LVM, NFS, etc) which are required by kernel.After that ...
9
votes
3answers
4k views

GRUB confuses kernels/initramfs of Ubuntu and Arch Linux installation

I have a machine that used to dual-boot Ubuntu (16.04 currently) and Windows 7, with Ubuntu's GRUB as boot loader. Now I just added Arch Linux as third OS, following the official installation ...
6
votes
1answer
4k views

Appending files to initramfs image - reliable?

I'm modifying a bunch of initramfs archives from different Linux distros in which normally only one file is being changed. I would like to automate the process without switching to root user to ...
3
votes
2answers
15k views

Missing root VG, dropped to an initramfs shell

My Linux Mint 17.1 (64-bit) uses LVM on its OS drive (an SSD). I must have done "something" to wreck my system, because last time I rebooted, the boot failed. Instead, I got the message "Alert! /dev/...
3
votes
1answer
2k views

How to set laptop screen brightness just after boot with full disk encryption

my girlfriend bought Lenovo Essential G500 i5-3230 and I installed Linux Mint 16 on it with full disk encryption. It is standard installation with encryption using dmcrypt and LUKS. But there is a ...
2
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1answer
3k views

ERROR: device '' not found. Skipping fsck (can't boot)

I have a Manjaro Linux installation and after a pacman - syu update (potentially updating the kernel) , and restarting my computer, I get the following error message after grub: [ 4.896409] Initramfs ...
2
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0answers
852 views

Booting over the LAN using uboot

I am trying to boot my beaglebone over the LAN. I am able to download the Kernel uImage from the TFTP server. Here is what I did - U-Boot SPL 2011.09-00053-gb423c52 (Aug 10 2012 - 11:26:55) Texas ...
2
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0answers
1k views

Why do I need to specify two init images - initrd and boot - inside KVM to boot to bash?

My machine is running inside a KVM virtual machine (Parallels Desktop v8), having a BIOS (not UEFI), having one SATA drive connected, one GPT partition on that disk, the partition is ext4 formatted, ...
2
votes
1answer
2k views

Where is fsck startet for the root filesystem at boot?

I want to extend an existing Debian 6.0 system so that it is able to automatically fix a corrupt root file system by restoring a separate image. That process should start automatically instead of the ...
1
vote
1answer
849 views

How to mount /usr at boot time without an initramfs?

I'm having trouble booting into my system with systemd installed. I wouldn't like to use an initramfs, so I use a self-configured kernel which starts my kernel with the following in-built command line:...
1
vote
2answers
108 views

Why are these mounts needed before updating initramfs?

After reading this answer on bind mount, I got the idea that a bind-mount in Linux is to reproduce part or an entire filesystem under another point in the directory tree. So when we write the ...
1
vote
1answer
297 views

Why does switch_root delete all the files in the initramfs?

WARNING: switch_root removes recursively all files and directories on the current root filesystem. -- man switch_root from util-linux, version 2.32-2.fc28.x86_64 Why?
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0answers
1k views

BusyBox on persistent USB Livesystem

I fiddled a bit with creating a Live USB stick for creating a LFS system on my new computer. To make this easier I wanted to store some persistent data on it as well (settings, GCC, make and such ...
1
vote
1answer
3k views

Ubuntu 16.04 stops booting, it has LVM and LUKS encryption configured, superblock restore already tried

Suddenly my Ubuntu 16.04 drops me into an initramfs prompt like this: BusyBox v.1.22.1 (Ubuntu 1:1.22.0-15ubuntu1) built-in shell (ash) Enter 'help' for list of built-in commands. (initramfs) ...
0
votes
0answers
360 views

build initramfs for different host

Cross compiling a kernel takes minutes, deploying the thing on the target machine takes an hour. Most of the time is spent generating the initramfs. Both the build host and the target run Fedora which ...