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 initramfs?
The initramfs is a complete set of directories that you would find on a normal root filesystem. It is bundled into a single cpio archive and compressed with one of several compression algorithms. At boot time, the boot loader loads the kernel and the initramfs image into memory and starts the kernel.
Why is initramfs needed?
initramfs is a root filesystem that is embedded into the kernel and loaded at an early stage of the boot process. It is the successor of initrd. It provides early userspace which can do things the kernel can’t easily do by itself during the boot process. Using initramfs is optional.
Why is Ubuntu booting to Initramfs?
The “initramfs” error can affright you, but luckily this error has a very easy and straightforward solution. This error occurs when your memory got corrupted, especially the drive containing the operating system, and does not let it boot. To fix it, simply use the “file system consistency check” or “fsck” utility.
What is BusyBox in Ubuntu?
BusyBox combines tiny versions of many common UNIX utilities into a single small executable. It provides minimalist replacements for most of the utilities you usually find in GNU coreutils, util-linux, etc. … To create a working system, just add /dev, /etc, and a Linux kernel.
How do I install initramfs?
Detailed Instructions:
- Run update command to update package repositories and get latest package information.
- Run the install command with -y flag to quickly install the packages and dependencies. sudo apt-get install -y initramfs-tools.
- Check the system logs to confirm that there are no related errors.
How does update initramfs work?
The update-initramfs script manages your initramfs images on your local box. It keeps track of the existing initramfs archives in /boot. There are three modes of operation create, update or delete. … At boot time, the kernel unpacks that archive into RAM disk, mounts and uses it as initial root file system.
How do I run initramfs?
Three commands must be run at the BusyBox command prompt.
- Run the exit Command. First enter exit at the initramfs prompt. (initramfs) exit. …
- Run the fsck Command. Use the fsck command with the file system path determined above. …
- Run the reboot Command. Finally enter the reboot command at the (initramfs) command prompt.
How does Busybox work?
Busybox allows you or programs to perform actions on your phone using Linux (copied from Unix) commands. Android is basically a specialized Linux OS with a Java compatible (Dalvik) machine for running programs.
How do I create an initramfs image?
Create the New Initramfs or Initrd
- Create a backup copy of the current initramfs: cp -p /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r).img.bak.
- Now create the initramfs for the current kernel: dracut -f.
What are the run levels in Linux?
A runlevel is an operating state on a Unix and Unix-based operating system that is preset on the Linux-based system.
…
runlevel.
| Runlevel 0 | shuts down the system |
|---|---|
| Runlevel 1 | single-user mode |
| Runlevel 2 | multi-user mode without networking |
| Runlevel 3 | multi-user mode with networking |
| Runlevel 4 | user-definable |
How do I manually fix fsck?
Repair Corrupted File System
- If you don’t know the device name, use fdisk , df , or any other tool to find it.
- Unmount the device: sudo umount /dev/sdc1.
- Run fsck to repair the file system: sudo fsck -p /dev/sdc1. …
- Once the file system is repaired, mount the partition: sudo mount /dev/sdc1.
How do I force fsck to reboot?
Resolution
- Identify the filesystem mounts you want to run FSCK against using “df”: …
- Create a file named “forcefsck” at the root folder of each desired filesystem to force the check on next reboot. …
- Reboot the CPM and you will notice upon reboot fsck executed via the console: