initrd is a method for loading a temporary file system into memory, during the process of booting the Linux kernel.

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Is it possible to put root in LVM without using initrd?

I have just set up a Gentoo base system (which means I can boot and log in and do stuff with it now). My root partition is in an LVM2 virtual group (with a separated /boot partition). In order to boot ...
8
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1answer
1k views

Why is my initial ramdisk so big?

I'm running Ubuntu 11.10, which came with kernel version 3.0.0-14. I downloaded and built a kernel from the 3.1.0 branch. After installing the new kernel, I see that my /boot/initrd.img-3.1.0 file is ...
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votes
2answers
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Add Apache to Ubuntu's startup

I'm currently learning the Linux environment, and decided to manually install the Apache server. For educational purposes, I've compiled it into: /server/apache The http.conf location is configured ...
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1answer
1k views

Is Ramdisk and initrd the same?

While reading through the kernel documentation on ramdisk in ramfs-rootfs-initramfs.txt i was having a doubt like the ramdisk explained there is same as the initrd features described in the post at ...
6
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2answers
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What does mkinitrd change when it adds kernel modules to the initrd?

When creating an initrd using mkinitrd (CentOS 5.5), the kernel modules it adds to the initrd get modified in the process. For example, the initrd's /lib/sata_via.ko is not binary identical to ...
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3answers
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Does /init (or /linuxrc) script creates temporary device nodes in /dev?

Considering that GRUB executes following lines: kernel /vmlinuz root=/dev/sda1 ro initrd /initrd On boot, how does the Linux kernel finds out about /dev/sda1 device node? I know that ...
5
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1answer
751 views

Adding files to initrd makes linux not be able to read it

I'm using clonezilla-1.2.12 and need to add the Broadcom firmware to the initrd so it can netboot. (clonezilla is debian-based and debian no longer includes the firmware blobs as they're non-free. ...
5
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1answer
320 views

How do I load initrd into memory to be passed to kernel when using kexec?

As the MIPS port of kexec doesn't support the --initrd param, I'm looking for workarounds to imitate the feature. According to Linux/MIPS wiki, MIPS kernels support rd_start and rd_size kernel command ...
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1answer
828 views

Booting without initrd

Is it possible to boot linux without a initrd.img ? I am planning to add default drivers as a part-of-kernel itself and avoid initrd completely. What are the modules that should be made ...
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2answers
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How does Linux load the 'initrd' image?

I've been trying to understand the booting process, but there's just one thing that is going over my head.. As soon as the Linux kernel has been booted and the root file system (/) mounted, ...
4
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1answer
944 views

How can I force a Ubuntu kernel to fail mounting / and drop into the initramfs rescue shell?

I am trying to customize the initramfs rescue environment and would like to force the kernel to fail mounting / and drop into the (initramfs) rescue shell, as opposed to single user mode. How can I ...
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2answers
3k views

Linux kernel is not finding the initrd correctly

I had compiled a linux kernel and I wanted to debug it in QEMU. I created a file to boot from by doing the commands $ qemu-img create -f raw disk.img 200M $ mkfs.ext2 -F disk.img # mkdir /mnt/rootfs ...
4
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1answer
819 views

Will a “customized” initrd survive a kernel update via yum?

I have a CentOS 5.5 installation with the stock CentOS 5.5 kernel. I have modified the init script in the initrd, commenting out some unneeded modules, lowering the interval time of the "stabilized" ...
3
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2answers
6k views

Ubuntu: How do the md devices get assembled at bootup?

How do the md devices get assembled at bootup in Ubuntu? Is /etc/mdadm/mdadm.conf truly the relevant factor here? My mdadm.conf is sound and I checked that while I was in the rescue CD environment. ...
3
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2answers
4k views

building my own initrd, how to populate dev directory

I am trying to learn stuff about initrd. I have followed this tutorial to build my own initrd from scratch, and I installed busybox on it. Then I made an .iso from it with isolinux, so I could test it ...
3
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1answer
2k views

vmlinuz and initrd not found after building the kernel?

After configuring and building the kernel using make, why don't I have vmlinuz-<version>-default.img and initrd-<version>.img, but only got a huge vmlinux binary (~150MB)?
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3answers
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Avoid pause during dm-raid initialization

On my CentOS 5 workstation I get a few seconds wait after dm-raid45 has been loaded ("Initializing Driver" or something like that). This seems to be part of the initrd. After that the system boots ...
3
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1answer
2k views

initramfs image compression other than gzip

can the initramfs image be compressed by a method other than gzip, such as lzma?
3
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1answer
315 views

Mount /etc from disc into squashfs

I've created a gentoo-live system which should be booted from a CF-card. The whole file-system is in a squashfs. I've created a custom initrd which first mounts the CF-card and from there the squashed ...
3
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1answer
578 views

Getting keyboard to work in debian 6.0 in order to unlock root partition

I just installed Debian 6.0, encrypted / and now I'm trying to boot. When GRUB comes up, I select Debian, it loads the initrd and asks for the root password, however I can't enter anything, because ...
3
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0answers
56 views

Are there any canned solutions for running sshd in the initrd?

This is mostly aimed at Debian/Ubuntu, but I feel savvy enough on a variety of distros to be able to adapt the solution for one distro to another. Here's my scenario. There are a few situations when ...
3
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1answer
192 views

initrd or ramfs for SLES as /

i would like to boot a SLES and run it out of a ramdisk. I would like to setup machines so that they start PXE boot and as part of the PXE boot process they pull across an image that is the root ...
3
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1answer
275 views

Create Logical Volume Snapshot at boot and before mount

I'm using Kubuntu 11.10 and before I upgrade to 12.04, I want to make snapshots of my filesystems. Coming to think of that, I realized that it can be very useful to create snapshots of logical volumes ...
2
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1answer
250 views

When would an initrd be necessary?

I've read that I can boot the kernel without initrd, and I've also read that additional modules are loaded during the initrd stage -- as I understand it, for necessary drivers that weren't included in ...
2
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1answer
188 views

How do i run a process in a specific directory?

In an init.d file i wrote the below. Now i need to make the bin run in a specific directory. How do i tell it which directory to use? mono --debug /path/bin &
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1answer
515 views

How to open the clonezilla initrd.img?

I am not understand why I get the error about initrd.img ( this initrd.img is the original file from clonezilla ISO file cp initrd.img /tmp zcat /tmp/initrd.img | cpio -idm zcat: initrd.img: not in ...
2
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1answer
58 views

Why is it that my initrd only has one directory, namely, 'kernel'?

I'm using debian live-build to work on a bootable system. By the end of the process i get the typical files used to boot a live system: a squashfs file, some GRUB modules and config files, and an ...
2
votes
2answers
560 views

Kernel freezes on loading ramdisk. How to find out what's wrong?

I'm using an Ubuntu Server (13.04) Minimal installation (with the Xubuntu Metapackage as a desktop environment, if that matters) on x86_64 on my Samsung notebook. I'm currently forced to use the ...
2
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1answer
1k views

Creating new initrd without installing kernel

How can i create initrd image for a new(experimental) kernel without actually installing it. (Existing tools to create initrd based on config and details from installed kernel.) Say i compile a new ...
2
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2answers
84 views

How can I remotely debug a broken initrd?

Background I have a system that runs Linux. It's a NAS, and does not have any monitor, keyboard, or serial port. It does have a network port. I'm not happy with the software running on it, and am ...
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0answers
345 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
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1answer
319 views

Booting grub-2.00 with 2 initrds, crashes with RAMDISK: incomplete write

So, I'm trying to split my initrd into two initrd's. There's some pretty significant scripts that run in the initrd, and we wanted to split the initrd so we could rev the just the logic or just the ...
2
votes
1answer
485 views

Script that unpacks a initrd, allows editing of the preseed.cfg and the packs it to cpio and gzip again

I want to program a script that allows what is said in the title. So basically I gunzip the initrd, than unpack the cpio, open vi to allow editing, save, pack with cpio, and gzip again, so nothing ...
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vote
3answers
447 views

Unpack, modify and pack initrd as a user

I've got a problem with rebuilding the initrd image as a user. Firstly, when I try to "unpack" the original initrd image: cpio -idm < initrd-base cpio: dev/tty8: Cannot mknod: Operation not ...
1
vote
1answer
72 views

Built new kernel, LVM won't mount from initrd

I need to upgrade my kernel on a RHEL 5 system to build with some experimental drivers. I have configured the kernel with module loading for LVM (dm_* modules). Once the initrd runs the /init ...
1
vote
1answer
145 views

Using qemu to boot OpenSUSE (or any other OS) with custom kernel

I want to run OpenSUSE as guest with a custom kernel image which is on my host machine. I'm trying: $ qemu-system-x86_64 -hda opensuse.img -m 512 -kernel \ ...
1
vote
1answer
691 views

Measurement of free ram through /proc/meminfo with ramdisk (initrd)

I am booting a disk image via PXE, it is a full system on an initrd ramdisk. I would like to measure the actual free memory of the system (not including buffers and file system caching). I was told ...
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2answers
421 views

Adding commands to initrd image [closed]

Whenever I enter into initrd prompt, I know that not every command is executed in that prompt. Can somebody tell me how I can add more commands support in that initrd prompt. It would be nice if you ...
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2answers
354 views

How to log the output of a daemon application?

I have a Java program running as a daemon (thanks to YAJSW, a wrapper for java). The thing is that this java application writes several lines of console text, (simply imagine a Hello World App). If I ...
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0answers
66 views

How can I replace root / filesystem with another filesystem?

When the Linux kernel starts up, it uses initrd as the root / filesystem, then replaces that with a filesystem partition in fstab. Based on a test in an early init script, I want to replace that root ...
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0answers
119 views

Build Mini Linux and Embedded Linux

How to build Mini Linux with Busybox, Kernel-3.15.3, Syslinux? I've built my Mini Linux using these steps: Steps in Building Base Mini Linux Distro 0 . Compile the kernel and see ...
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0answers
97 views

How to show progress when loading initrd?

I have a complete root fs built into initrd, so it's almost 500MB. It takes a while to load to memory and during this time, the screen has no indication of the progress. I would like to know if there ...
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0answers
175 views

How customize initrd via linuxrc

I have the need to use the same disk and so the same bootloader on devices with different motherboard. Each motherboard has it's own way of mapping devices so sometime the bootdisk is mapped ad hda ...
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0answers
204 views

not all initrd.img's are born equal?

I am trying to get a Red Hat 5.8 box booting via pxe. The box is a virtual machine on ESX5.0 it has a Paravirtual SCSI Controller and VMXNET3 network driver. Now these drivers do not come default in ...
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0answers
271 views

Configure vmware-tools without an initrd image?

Is it possible to run vmware-tools without an initrd? I don't know why I should use an initrd and it makes my kernel compilation more complicated. I can boot into my kernel without initrd but when I ...
0
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1answer
75 views

qemu can't run linux kernel

I saw this question and I did pretty much the same but I enabled initrd in configuration to use temporary root file system and no other modification but I still get this error on: qemu -kernel ...
0
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1answer
109 views

How are the services exactly starting in (K)Ubuntu?

I have latest Kubuntu. I have installed mysql. I was looking into the /etc/init. I see the following: In /etc/init/mysql.conf description "MySQL Server" ...
0
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2answers
715 views

Kernel/grub : how override root parameter inside initrd script

I have an old kernel ( 2.4.37.9 ) and I want to override or substitute the root=XXXXX parameter to send to the kernel inside the initrd script. I already made some attempt to do that but it seems ...
0
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1answer
710 views

How to create initrd.img from initrd.lz

I need to create initrd.img file from initrd.lz file. How may I do this?
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0answers
22 views

Install entire Linux OS to RAM disk

How would I install an entire Linux distro to a RAM disk, not just the kernel and modules with mkinitrd? Would I just need to make a huge initrd image? If so, how would I do that? thanks