[SOLVED] initrd not being read correctly by grub?

chexmix · 05-12-2016, 06:50 AM

Hi all -

I have noticed since switching to grub that the modules added by mkinitrd (jbd2, mbcache, ext4) fail to load at boot. I'd post the bootup messages, but I can't find them in dmesg output.

They don't show up in the output of lsmod.

When I look at the entries in /boot/grub/grub.cfg, I see

Code:

menuentry 'Slackware-14.2 GNU/Linux' --class slackware-14.2 --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-5b9e6f1c-e84c-4b09-b9f6-0cacb682f2ea' {
        load_video
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos3'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos3 --hint-efi=hd0,msdos3 --hint-baremetal=ahci0,msdos3  5b9e6f1c-e84c-4b09-b9f6-0cacb682f2ea
        else
          search --no-floppy --fs-uuid --set=root 5b9e6f1c-e84c-4b09-b9f6-0cacb682f2ea
        fi
        echo    'Loading Linux 4.4.9 ...'
        linux   /boot/vmlinuz-huge-4.4.9 root=UUID=5b9e6f1c-e84c-4b09-b9f6-0cacb682f2ea ro  
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.gz
}

... why 'msdos'? Is this causing the loading of ext4, mbcache and jbd2 to fail?

Thanks,

Glenn

Emerson · 05-12-2016, 07:08 AM

msdos is the partition type.

aragorn2101 · 05-12-2016, 07:41 AM

Hi,

You are booting a huge kernel, maybe the problem is some kind of conflict. Try not loading the initrd with the huge kernel and then try booting a generic kernel with the initrd, then compare.

keefaz · 05-12-2016, 07:42 AM

Quote:

Originally Posted by chexmix

Hi all -

I have noticed since switching to grub that the modules added by mkinitrd (jbd2, mbcache, ext4) fail to load at boot. I'd post the bootup messages, but I can't find them in dmesg output.

They don't show up in the output of lsmod.

It's not grub, you're using kernel huge which has drivers as built-in, not as modules

jpollard · 05-12-2016, 07:48 AM

Normally, the initrd for a specific kernel is created for that specific kernel.

The initrd for each contains things that may be specific to that kernel (either by version number, driver identification, specific drivers included/missing).

The initrd for the huge kernel would/should not try to load modules that are already built in - it WILL cause problems.

A generic kernel should use a generic initrd...

chexmix · 05-12-2016, 07:48 AM

OK. Why is the initrd not getting read correctly? or maybe the boot messages are spurious?

I've been having lots of issues with my Slackware installs lately, and have a large project due Saturday -- would love to start getting them ironed out. Since this one seems fundamental, I'm starting here.

jpollard · 05-12-2016, 07:49 AM

The boot messages MAY be spurious in that the initrd is directing the installation of modules that don't apply to that kernel.

It MAY be more serious if the boot doesn't complete.

chexmix · 05-12-2016, 07:54 AM

I think you folks hit it. Back in a few ...

Didier Spaier · 05-12-2016, 08:02 AM

Quote:

Originally Posted by chexmix

OK. Why is the initrd not getting read correctly?

Because, as others have already pointed out, there is no need to load as modules drivers that are already included in the kernel.

In other words, you can either use:

a huge kernel without an initrd.
or a generic kenel with an initrd.

Using an initrd with a huge kernel, although probably harmless, is pointless. Why are you doing that?

jpollard · 05-12-2016, 09:08 AM

Quote:

Originally Posted by Didier Spaier

Because, as others have already pointed out, there is no need to load as modules drivers that are already included in the kernel.

In other words, you can either use:

a huge kernel without an initrd.
or a generic kenel with an initrd.

Using an initrd with a huge kernel, although probably harmless, is pointless. Why are you doing that?

Sometimes, a minimal initrd is useful for catching hardware errors. The initrd IS, after all, a minimal root system and can be used to rebuild/recover a system.

Didier Spaier · 05-12-2016, 10:09 AM

Quote:

Originally Posted by jpollard

The initrd IS, after all, a minimal root system and can be used to rebuild/recover a system.

Yes, and that is the case for the Slackware installer. But I don't see a need for that in the issue brought by the OP.

jpollard · 05-12-2016, 10:18 AM

No - that just looks like adding things to an initrd that aren't appropriate for that specific kernel, or just using the wrong initrd.

Richard Cranium · 05-12-2016, 11:55 AM

If you want to use a generic kernel with an initrd with grub2, see https://www.linuxquestions.org/quest...ml#post5078462

hazel · 05-12-2016, 12:01 PM

Quote:

Originally Posted by chexmix

Hi all -

I have noticed since switching to grub that the modules added by mkinitrd (jbd2, mbcache, ext4) fail to load at boot. I'd post the bootup messages, but I can't find them in dmesg output.

They don't show up in the output of lsmod.

When I look at the entries in /boot/grub/grub.cfg, I see

Code:

menuentry 'Slackware-14.2 GNU/Linux' --class slackware-14.2 --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-5b9e6f1c-e84c-4b09-b9f6-0cacb682f2ea' {
        load_video
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos3'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos3 --hint-efi=hd0,msdos3 --hint-baremetal=ahci0,msdos3  5b9e6f1c-e84c-4b09-b9f6-0cacb682f2ea
        else
          search --no-floppy --fs-uuid --set=root 5b9e6f1c-e84c-4b09-b9f6-0cacb682f2ea
        fi
        echo    'Loading Linux 4.4.9 ...'
        linux   /boot/vmlinuz-huge-4.4.9 root=UUID=5b9e6f1c-e84c-4b09-b9f6-0cacb682f2ea ro  
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.gz
}

... why 'msdos'? Is this causing the loading of ext4, mbcache and jbd2 to fail?

The modules that grub loads are modules for the grub kernel. For example, part_msdos is the module that reads the partition table of a msdos-partitioned disk (i.e. a traditional disk with an mbr).

What modules get loaded into your Linux kernel once it's loaded depends on how the kernel reads your hardware and what you have in your initrd's /etc/modprobe.d directory.

chexmix · 05-12-2016, 07:43 PM

Quote:

Originally Posted by chexmix

I think you folks hit it. Back in a few ...

OK. More than a few, but not quite solved ...

I've removed what I thought was everything having to do with the 'huge' kernel from my system, re-ran both 'grub-install' and 'grub-mkconfig' ... and when I try to boot the first selection presented to me upon restarting, I find that the menu entry still has 'huge' where it should have 'generic'.

Of course I can edit it upon boot, but that's a drag. And I'd love to know where 'grub-mkconfig' is getting its information (somewhere in /etc/grub.d/ I guess). I could also disobey the orders at the top of grub.cfg and edit it directly, but I assume those edits would be overwritten next kernel upgrade when I have to run 'grub-mkconfig' again.

Next I'm going to try uninstalling and re-installing the grub package, in case something is set during that process.

- Glenn