kernel, boot, grub

[jankom]

I just have a simple question:
How important, or is it necessary, to have a line in my /etc/portage/make.conf file

[Ralphred]

The GRUB_PLATFORM setting is really only used by the user when "installing the bootloader", as a function of grub-install. Grub still supports installing it's bootloader binary(s) directly to MBR*, or as an EFI compatible binary in a suitable place/partition**. If the machine is booting to the point grub is being loaded, and in turn is trying load the kernel, until you need to update the grub binaries by running grub-install then GRUB_PLATFORM won't cause you an issue. If you are unsure you can build grub with GRUB_PLATFORMS="efi-64 pc" and specify which to use at the time of running grub-install.

*Requires grub to be built with GRUB_PLATFORMS="pc"
**Requires grub to be built with GRUB_PLATFORMS="efi-64"

[pietinger]

jankom,

the most common cause for a kernel panic at system startup is that the kernel receives (in this case FROM grub) incorrect information about its root partition (this is the kernel command line parameter “root=...”). But if root= is correct for you, then it would be helpful to get all the exact information of the kernel panic (if necessary by photo). The second most common cause is that the kernel is missing the modules it needs to access the root partition; see more here: https://forums.gentoo.org/viewtopic-p-8688524.html#8688524
_________________
https://wiki.gentoo.org/wiki/User:Pietinger

[jankom]

Thank you - my simple question is answered. Apparently when I installed the gentoo system on my home pc I followed the gentoo instructions and added the GRUB_PLATFORMS definition.

As far as the linode gentoo boot kernel panic is concerned I think it is a linode issue. Originally I purchased the linnode computing instance in 2018 with xubuntu OS. Later on I decided to make it gentoo and similar to my home gentoo pc. However, I built my home gentoo pc with downloaded gentoo image for gui desktop
[5] default/linux/amd64/17.1/desktop (stable) *
and later updated to
[46] default/linux/amd64/23.0/split-usr/desktop (stable) *
based on eix-sync update notes at the time.
The linode computing instance was built automatically by Akamai linode selecting a gentoo OS. Initially the gentoo profile was
[1] default/linux/amd64/17.1 (stable) *
and later updated to
[45] default/linux/amd64/23.0/split-usr (stable) *
based on eix-sync update notes just like home pc.

However, I noticed that uname -r on linode was different than /usr/src/linux from ex-syn operations. I've contacted the linode Customer Support, and while they were eager to help could not really explain and solve the dilemma; they often referred me to gentoo.

After your answers I tried all sorts of things with gub, but ended up with boot failures and rescue disk; linode has a rescue boot option on their web console where I can access my linode disk, make change an do chroot.

I ended up with using the current linode kernel, i.e. booting from somewhere else, not using /boot and grub files.

Thanks for the quick reaction and answer to my "simple question". I'll mark this topic as SOLVED.

jankom (janos)

P.S.
Here is the kernel panic:

[pietinger]

[jankom]

Great information, THX.
Now I understand the boot process a little better, the role of initramf. What generates the initramfs? On my home pc it is always there after I compile an updated kernel, and I don't issue installkernel command. Everything works at home whenever I update the kernel (make, make install, make install-modules, etc.)

My home pc has installkernel, but my linode computing instance does not.

The currently working linode is:

[Ralphred]

[jankom]

[Ralphred]

[pietinger]

jankom,

we need more informations ... because your linode is a bit unusual ... and gives us some questions ->

a) you said you want boot 6.6.53 ... but there is no 6.6.53 in your /boot ?!
b) /boot/vmlinuz-6.1.31-gentoo-x86_64 (and all other files) have a date from today ?! Why?
c) I see only sda and sdb (being root-partition and swap) ... but where is grub installed ? I mean the 1st part of grub (not the 2nd part of grub residing in /boot/grub)
d) What can you boot ? Gentoo ? Which version? (uname -a) or XubuntuOS? Did you ever run Gentoo here?
e) How have you installed Gentoo on Linode? Booting with our GentooLiveCD? and then installing with AMD64 Handbook? Or other methods?
f) Do you use gentoo-sources at your home or our (binary) distribution kernel? (or genkernel?) You said: You do at home "make && make install && make modules_install" (this smells for gentoo-sources or genkernel) ... do you use at home "dracut" (or "ugrd") -> Do you want to do the same here ? ->
g) How you have installed the kernel here on Linode? Was it 6.1.32? A Gentoo-kernel? Or was it pre-installed?

So, I would like to ask you:

1. Tell us everything what has worked in the past until day X.
2. What happend on day X / what have you tried to do (detailed steps)
3. What have you renamed (from/to)?

To see more clear we would need more then lslbk and blkid ... best would be the "dmesg" of that thing/OS you can boot here; this tells us also something about the used hardware. Also a "lspci -nnk" and a "lsmod" (Please use wgetpaste for dmesg). Does "efibootmgr" gives you some results or is this not an UEFI system? Does "zcat /proc/config.gz" gives you the configuration of the current running kernel? If yes, put it in a file and give it also to us ...

... and many answers from above questions.

Before trying anything else ... we should know the current situation and understand it ... not to make more damage (as we already have ).
_________________
https://wiki.gentoo.org/wiki/User:Pietinger

[jankom]

[pietinger]

[jankom]

wgetpaste done for 3 .txt files. I did the file generation commands in an ssh terminal from my home pc, then sshfs mounted my linode home directory to my home gentoo pc and issued the wgetpaste command from my home pc.