[SOLVED][GRUB update] change partition to load

[ade05fr]

hello

i recently have a crash disk and i had to recreate a new partition of my home folder.
But now i want to change my boot load through grub

in fact before i had to load through my internal HDD and now i want to launch my image through an external USB HDD

here is what i have

[NeddySeagoon]

ade05fr,

Go into your BIOS and set it to boot from your external hard drive.

The external hard drive will need grub installed to its MBR.
As root is on USB and you have no initrd. USB and usb-storage must be built into the kernel.
Lastly, you will need a new kernel parameter for the USB. rootdelay=7
This allows 7 seconds for the USB subsystem to get started before the kernel tries to mount root. The normal course of events is to mount root first, then start USB, thats doomed to fail with root on USB.

To add to the interest, your USB drive may now be /dev/sda
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[ade05fr]

hello

now i'm able to boot through my USB Key but i have another problem.
In fact when my kernel is loaded the /dev/root is linked to my internalHDD partition instead of the partition
from my external USB drive.

here is what i have in dmesg

[jburns]

If you are building the kernel without genkernel real_root=/dev/sdc7 should be root=/dev/sdc7.

[ade05fr]

its not working at all

but if i check in my bzImage here is what i have

[Stonic]

you have edited /etc/fstab to reflect the new partition as well? Just a thought

[ade05fr]

yep

[Stonic]

Hmm. So you followed NeddySeagoon's instruction and installed the MBR onto hd1 instead of hd0 correct? Otherwise I got nothing else for you sorry D:

[ade05fr]

yes as i indicate in my grub.conf.
_________________
[LAPTOP]
DELL Inspiron 5110
i5-2450M CPU @ 2.50GHz
[LINUX-GENTOO]
Gentoo 2018-0
kernel 5.0.6
gnome 3.30

[ade05fr]

up

a weird thing, my external usb disk is loaded 20 seconds after the boot of my kernel
i think that my partition is not visible before.

[NeddySeagoon]

ade05fr,

[ade05fr]

hi

i have finally succeeded to boot without initrd but now i have problems during boot sequence through init.d
The /dev, /proc have problem to be mount and lib modules can be loaded normally.

do i have to check something in the kernel config file before compiling ?

another thing, i had to hardcode in /usr/src/linux/arch/x86/boot/Makefile

[NeddySeagoon]

ade05fr,

Do you have exact error messages please.
Hardcoding your root in /usr/src/linux/arch/x86/boot/Makefile should not be needed.

Sight of your kernel .config file would be useful. wgetpaste will put it on a pastebin, as it won't fit in a forums post.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[ade05fr]

hello

here is my config file
http://pastebin.com/Zu98V27s

and here is what happen next
grub.conf updated

[ade05fr]

hello again


finally i have found a cue but i have to test it tonight when i come back home.

In fact it seems that i have to set in the config file these 2 parameters

[cach0rr0]

had a discussion on devtmpfs a short while ago, if you fancy reading

https://forums.gentoo.org/viewtopic-t-867707.html

all enabling those two settings should do, is create a /dev filesystem in memory containing all of your device nodes (e.g. block devices, character devices), rather, all of the ones that kernel you've built supports and can recognize. Without an initramfs, i dont know of much that would make use of it at the moment.

If things become too horribly confusing/cumbersome, you should actually be able to boot by the partition's UUID, or, my preference, using something like e2fslabel and booting by LABEL=whatever for root=
_________________
Lost configuring your system?
dump lspci -n here | see Pappy's guide | Link Stash

[ade05fr]

hello

i have tested and now it starts but i have problem to mount shmfs, procfs, devfs
it always says that

[ade05fr]

hello everyone

i have almost finished my restore configuration.
i have changed the root device by LABEL id in grub.conf.

[cach0rr0]

the biggest difference i see, is that on the left you have the USB drivers as built-in, instead of as modules
modules of course being loaded from the root fs, so if that root fs is on the usb drive, i would not expect it to work at all (unless of course you have an initramfs)

also worth pointing out, just a semantic issue, but 'devfs' is gone, dead, buried. Now is all udev, and devtmpfs while performing some similar tasks, is not strictly speaking devfs. Not that it matters a ton of things are working, but who knows who might stumble on this thread later and be confused
_________________
Lost configuring your system?
dump lspci -n here | see Pappy's guide | Link Stash