Why bind to LiveCD /proc before building initramfs ? Post: 303001550

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Top Forums UNIX for Beginners Questions & Answers Why bind to LiveCD /proc before building initramfs ? Post 303001550 by sreyan32 on Monday 7th of August 2017 07:34:11 AM

08-07-2017

Registered User

Why bind to LiveCD /proc before building initramfs ?

Imagine I have an unbootable system where I need to update the kernel image using

Code:

update-initramfs

.

I have seen numerous examples online which show the following

Code:

$ mount -t proc none /mnt/ubuntu/proc
$ mount -o bind /dev /mnt/ubuntu/dev
$ mount -o bind /sys /mnt/ubuntu/sys

After that we chroot into the broken OS and then execute the command to update the initramfs.

My questions are as follows-:

Are we binding the /proc and /dev of the Live CD to the broken system ? Or are we binding the /proc and /dev of the broken system to the live cd ?
If building the initramfs is dependent on the information of the OS for which the initramfs is built then won't it contain erroneous information if we build for the Live CD ? That is use the /proc and /dev of the LiveCD ?

Last edited by rbatte1; 08-07-2017 at 09:47 AM.. Reason: Tidied up numbered list

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mkinitrd

MKINITRD(8)							      dracut							       MKINITRD(8)

NAME

       mkinitrd - is a compat wrapper, which calls dracut to generate an initramfs

SYNOPSIS

       mkinitrd [OPTION...] [<initrd-image>] <kernel-version>

DESCRIPTION

       mkinitrd creates an initramfs image <initrd-image> for the kernel with version <kernel-version> by calling "dracut".

	   Important
	   If a more fine grained control over the resulting image is needed, "dracut" should be called directly.

OPTIONS

       --version
	   print info about the version

       -v, --verbose
	   increase verbosity level

       -f, --force
	   overwrite existing initramfs file.

       *--image-version
	   append the kernel version to the target image <initrd-image>-<kernel-version>.

       --with=<module>
	   add the kernel module <module> to the initramfs.

       --preload=<module>
	   preload the kernel module <module> in the initramfs before any other kernel modules are loaded. This can be used to ensure a certain
	   device naming, which should in theory be avoided and the use of symbolic links in /dev is encouraged.

       --nocompress
	   do not compress the resulting image.

       --help
	   print a help message and exit.

AVAILABILITY

       The mkinitrd command is part of the dracut package and is available from https://dracut.wiki.kernel.org

AUTHORS

       Harald Hoyer

SEE ALSO

       dracut(8)

dracut								    06/12/2014							       MKINITRD(8)