The root filesystem is on LVM and its required drivers and tools are not on the root filesystem yet.
Reach the root filesystem immediately after the kernel starts.
What is initramfs used for?
initramfs provides an early userspace in memory to prepare storage, encryption, and drivers before switching to the real root filesystem.
Detailed explanation
Incorrect. Login shells are started much later by the normal user-space system.
Incorrect. Login shells are started much later by the normal user-space system.
Incorrect. Firmware setup is handled before the kernel and initramfs.
Incorrect. Firmware setup is handled before the kernel and initramfs.
Incorrect. Persistent application data belongs on normal filesystems, not the temporary initramfs.
Incorrect. Persistent application data belongs on normal filesystems, not the temporary initramfs.
Correct. initramfs supplies the early tools and drivers and then switches to the real root.
Correct. initramfs supplies the early tools and drivers and then switches to the real root.
Try it yourself
An example you can run in a temporary verification environment.
ls /boot/initr* 2>/dev/null || echo 'initramfs image is not exposed in this environment'Expected result
通常環境ではinitrd/initramfsイメージ。コンテナやWSLでは未表示の場合があるKey points
- Early userspace
- Drivers needed to reach root
- Switch to the real root
Notes
- Environment: Linux / initramfs概念
- Command output formatting can vary slightly by distribution or tool version.
- Run the example in a temporary directory or process when possible.
Foundation review
Read the scope first
Check whether the command acts on the current shell, a new process, an existing process, or a file.
Verify the observable result
Use the supplied command and compare the output with the expected result.