GRUB2 Kernel Panic Rootfs failing to boot: VFS: unknown-block (0,0)

luzion · 07-11-2019, 02:13 PM

Newbie Gentoo user and on reboot it gives this error.
It is a dual boot machine with the BIOS/MBR partition table:

Code:

/dev/sda1 bootable  ntfs 100M windows ntfs
/dev/sda2 40G windows ntfs 
/dev/sda3 / noatime ext4 
/dev/sdb2 swap 20G
/dev/sdb3 /home noatime ext4

luzion · 07-11-2019, 08:52 PM

luzion · 07-11-2019, 09:12 PM

luzion · 07-11-2019, 09:17 PM

I haven't had a problem before with using the NTFS windows boot partition with linux, but it could be that Gentoo has a problem with it.
GRUB even has msdos (ntfs) modules built in. It can't be the filesystem.

The problem is the kernel panic, failing to boot after selecting the GRUB Gentoo kernel. It gives the unable to sync VFS unknown-block(0,0) message and I have to hard shutdown. I googled the message and so far I've tried to verify the grub.cfg is correct, and the HDD controller drivers are loaded.

RickDeckard · 07-11-2019, 10:41 PM

Well, for starters I'd imagine you haven't even begun to clearly specify the problem you're having here. What is going on? Is your system failing to boot? Are you hanging? What messages are you receiving? Your partition layout is not an error message, it's just a listing of disks. What is the operation you expect or don't expect? At what stage of reboot is it happening?

Secondly -- I'll take a wild guess and say this is your problem here -- NTFS (the default filesystem in Microsoft Windows) should not even be remotely close to selectable for a Linux partitioning scheme, let alone for /boot which is where your kernel resides. You should be using ext4 or heck, even ext2.

colorpurple21859 · 07-12-2019, 05:53 AM

you say your boot partition is /dev/sda1, but in grub gentoo menu entry you have

Code:

set=(hd0,3)
linux /boot/vmlinuz root=/dev/sda3

not

Code:

set=(hd0,1)
/vmlinuz root=/dev/sda3

or your missing some obscure driver you system needs loaded.

luzion · 07-24-2019, 10:08 PM

Quote:

Originally Posted by colorpurple21859

you say your boot partition is /dev/sda1, but in grub gentoo menu entry you have

Code:

set=(hd0,3)
linux /boot/vmlinuz root=/dev/sda3

not

Code:

set=(hd0,1)
/vmlinuz root=/dev/sda3

or your missing some obscure driver you system needs loaded.

I changed that parameter to be (0,1). Where could I start in finding if its a missing driver?
Gentoo's manual also recommends for MBR legacy machines like mine that there be a BIOS boot partition for grub from 2048 to +2M, but I followed the guide that mentioned installing Windows first was okay(hence using the windows boot partition), but maybe adding one now could fix it? This would fix what someone else mentioned about Linux not being able to boot on an NTFS partition.
Any suggestions are appreciated as I'm lost here.

hazel · 07-25-2019, 04:54 AM

It's a bit late in the day, but I would have said "Don't use Gentoo!" It has a lot going for it (bleeding edge software and the most freedom of choice of any distro), but it is definitely for experts only.

As far as the BIOS boot partition is concerned, you need one to accommodate the second stage of GRUB if you have a GPT disk booting from a BIOS. If it's a traditional DOS MBR disk, you don't need one because GRUB Stage 2 will fit into the gap between the MBR and the first partition.

colorpurple21859 · 07-25-2019, 05:05 AM

I reread this thread, let see if I got this straight, you get a grub menu, you select the entry you want to boot, up comes a few lines of code, then the message

Quote:

Kernel Panic Rootfs failing to boot: VFS: unknown-block (0,0)

If that is true then has nothing to do with grub. Your most likely missing a kernel driver to boot your system. what are the last several lines displayed on the screen before it locks up? How did you compile the kernel.

luzion · 07-25-2019, 02:07 PM

Quote:

Originally Posted by hazel

It's a bit late in the day, but I would have said "Don't use Gentoo!" It has a lot going for it (bleeding edge software and the most freedom of choice of any distro), but it is definitely for experts only.

As far as the BIOS boot partition is concerned, you need one to accommodate the second stage of GRUB if you have a GPT disk booting from a BIOS. If it's a traditional DOS MBR disk, you don't need one because GRUB Stage 2 will fit into the gap between the MBR and the first partition.

I appreciate your advice Gentoo is over my head! The handbook listed the example partitioning for BIOS/MBR to include a BIOS boot. I looked at the quick guides and complete guides as well and they confirm that it's not needed.

Quote:

Originally Posted by colorpurple21859

what are the last several lines displayed on the screen before it locks up?

The last lines are "cpu:3 pid: 1 Comm: swapper/0 not tainted 4.19.57-gentoo #2", a call trace, Kernel offset relocation range, and the kernel panic not syncing root fs error. I tried to find the whole output but it was not in /var/log/.

Quote:

Originally Posted by colorpurple21859

How did you compile the kernel.

Manually, using the guide first and safe C/USE flags, then referencing someone else's configuration on a similar machine and emerging* again.
*make

colorpurple21859 · 07-25-2019, 03:34 PM

try using genkernel or boot into the medium used to install Gentoo and run lsmod to see what modules are loaded and compare to what you have built in your kernel.