[SOLVED] LFS 7.5 Kernel Panic Error

kamils096 · 05-27-2014, 03:30 PM

Hi, i'm reading LFS 7.5 book, and i stuck in one chapter: Booting the LFS. I compiled kernel many times, i tries to change grub config and it's nothing help. I use VMWare Workstation, base system, where i build LFS, is Debian Testing. When i choose LFS from GRUB menu, kernel is starting and a moment later i get message from VM, that CPU is halted by Virtual Machine. On screen there is a information:
kernel panic-not syncing: VFS: unable to mount root fs on unknown block(0,0)

What's wrong? Here it's my GRUB config:

Code:

# Begin /boot/grub/grub.cfg
set default=0
set timeout=5

insmod ext2
set root=(hd0,3)

menuentry "GNU/Linux, Linux 3.13.3-lfs-7.5" {
        linux   /boot/vmlinuz-3.13.3-lfs-7.5 root=/dev/sda3 ro
}

and here it's my kernel config:
http://pastebin.com/u9vxf0BC

What's wrong? I really want to know where is problem. Thank you in advance for help. I'm sorry for mistakes in my message, my English isn't perfect.

dijetlo · 05-28-2014, 01:06 PM

Quote:

insmod ext2

I don't know a lot about grub.
I know less about...um... the rest of what you said.
(it's not your English, btw, I'm just a moron)
But I do know what ext2 is, and it aint...whatever you said.

Could that be your problem?

kamils096 · 05-28-2014, 01:50 PM

Thanks for your reply, but grub isn't my problem. insmod ext2 covers ext3 and ext4 too, when i tried to boot Debian with same options as LFS(of course, antoher partition and kernel, and i add initrd option), they boot successfull. I done a little experiment - i load Debian kernel, but i choose LFS partition as root partition for kernel. I got same error, as i wrote in first post. When i try to load Debian with LFS kernel i've got a same kernel panic. I don't know what's wrong, i suspect kernel config, but my lfs root partition may be bad. How can i fix that problem?

ReaperX7 · 05-28-2014, 07:11 PM

Did you check your /etc/fstab first?

kamils096 · 05-29-2014, 10:48 AM

Here it's my fstab from LFS system:

Code:

# Begin /etc/fstab

# file system  mount-point  type     options             dump  fsck
#                                                              order

/dev/sda3     /            ext4    defaults            1     1
# /dev/sda2     swap         swap     pri=1               0     0
proc           /proc        proc     nosuid,noexec,nodev 0     0
sysfs          /sys         sysfs    nosuid,noexec,nodev 0     0
devpts         /dev/pts     devpts   gid=5,mode=620      0     0
tmpfs          /run         tmpfs    defaults            0     0
devtmpfs       /dev         devtmpfs mode=0755,nosuid    0     0

# End /etc/fstab

Edit: I finally boot my LFS system, but with Debian kernel and initrd. I use these options:

Code:

insmod ext2
set root=(hd0,1)

menuentry "GNU/Linux, Linux 3.13.3-lfs-7.5" {
        linux   /boot/vmlinuz-3.14-1-amd64 root=/dev/sda3 ro
        initrd /boot/initrd.img-3.14-1-am64
}

LFS system with Debian kernel work fine, so this is kernel issue, not a file system or another. I made a mistake in kernel config, but i don't know where.

Edit: Yes, i finally did it, my LFS system boot sucessfull with own kernel. I make config again and i find VMWare PVSCSI driver. When compile it to kernel, my LFS system boot without problems. Thanks for you replies.

jbhv12 · 02-14-2018, 02:29 PM

Quote:

Originally Posted by kamils096

Edit: Yes, i finally did it, my LFS system boot sucessfull with own kernel. I make config again and i find VMWare PVSCSI driver. When compile it to kernel, my LFS system boot without problems. Thanks for you replies.

hi there. I'm having the exact same problem. Can you please post your kernel config file? Thanks.

spiky0011 · 02-15-2018, 11:32 AM

have a look at this config pay attention to any vm stuff
http://www.linuxfromscratch.org/~kre...sic-kernel.txt

TechLearner · 05-31-2021, 04:40 PM

I was also facing the same problem i.e. kernel panic-not syncing: VFS: unable to mount root fs on unknown block(0,0) with the LFS 10.1 version. I was using VMware Workstation pro. The problem was with the kernel configuration. While doing the LFS on virtual machine we have to select some extra options in menu config. I referred this blog https://blog.andreev.it/?p=729 and was easily able to solve the issue.
Refer the menu config part from the site given above if facing the same problem.

Keith Hedger · 06-01-2021, 02:50 PM

version 7.5 of the lfs book is really old you should really be using 10.1/stable version

sodacris · 12-02-2022, 10:31 PM

Quote:

Originally Posted by TechLearner

I was also facing the same problem i.e. kernel panic-not syncing: VFS: unable to mount root fs on unknown block(0,0) with the LFS 10.1 version. I was using VMware Workstation pro. The problem was with the kernel configuration. While doing the LFS on virtual machine we have to select some extra options in menu config. I referred this blog https://blog.andreev.it/?p=729 and was easily able to solve the issue.
Refer the menu config part from the site given above if facing the same problem.

yes, it finally boots. plus I was using lfs 11.2