Re: [gentoo-user] Kernel does not boot after adding a new SATA drive

[Mike Gilbert]

On Tue, Sep 6, 2016 at 6:03 PM, gevisz <gevisz@×××××.com> wrote:
> 2016-09-07 0:32 GMT+03:00 Neil Bothwick <neil@××××××××××.uk>:
>> On Wed, 7 Sep 2016 00:05:32 +0300, gevisz wrote:
>>
>>> >> But it seems that GRUB does not read fstab... :(
>>> >
>>> > It does not, because it has not loaded the kernel yet, so it cannot do
>>> > anything on the system.
>>>
>>> Oh, poor little Grand Unified Boot Loader!
>>>
>>> It cannot do anything! Even to read fstab by its grub-mkconfig script!
>>
>> We were talking about GRUB the bootloader, not grub-mkconfig the Linux
>> program to write grub.cfg. As you were asking whether you should run
>> grub-mkconfig again, it seems reasonable to assume that you haven't run
>> it since adding the disk, not that it should make a difference.
>>
>>> P.S. I usually run grub-mkconfig when kernel is already loaded!
>>>       And in my fstab all the disks are refered by UUID!
>>>
>>
>> grub-mkconfig doesn't care about the fstab of the running distro since it
>> scans your drives for all operating systems it can boot.
>>
>> Either look in grub.cfg to see what it going on or post it here along
>> with the exact error messages so others may try for you.
>>
>
> I have added the following line to the /etc/default/grub
>
> GRUB_CMDLINE_LINUX="root=UUID=44***"
>
> run
>
> # grub-mkconfig -o /boot/grub/grub.cfg
>
> and got in  the following entry
>
> ### BEGIN /etc/grub.d/10_linux ###
> menuentry 'Gentoo GNU/Linux' --class gentoo --class gnu-linux --class
> gnu --class os $menuentry_id_option 'gnulinux-simple-44***' {
>     load_video
>     insmod gzio
>     insmod part_msdos
>     insmod ext2
>     set root='hd1,msdos3'
>     if [ x$feature_platform_search_hint = xy ]; then
>       search --no-floppy --fs-uuid --set=root --hint-bios=hd1,msdos3
> --hint-efi=hd1,msdos3 --hint-baremetal=ahci1,msdos3
> --hint='hd1,msdos3'  44***
>     else
>       search --no-floppy --fs-uuid --set=root 44***
>     fi
>     echo    'Loading Linux 4.4.6-gentoo ...'
>     linux    /boot/vmlinuz-4.4.6-gentoo root=/dev/sdb3 ro
> }
>
> wich, in my view, does not differ a lot from what was before.
>
> The 44*** denotes the UUID of my boot partition.
>
> Will try it tomorrow and report.
>

grub-mkconfig is not finding an initramfs, as evidenced by the lack of
an "initrd" in in grub.cfg.

If it is unable to find an initramfs, it will always output
root=/dev/sdX instead of root=UUID=...