Kernel panic while running iso on kvm/qemu
 

Hi,

recently I tried to create custom debian installer cd (based on Wheezy 7.1) I decided to run it in virtualization environment through virt-manager (qemu/kvm), previously I created iso image and my own isolinux.cfg file which I had put in /isolinux, other files in that directory remained unmodified, also I made a path with preseed file. Unfortunately after creating a machine with storage and initializing boot sequence, kernel panicked:

Content of isolinux.cfg:

GNU nano 2.2.6 File: isolinux.cfg Modified

# D-I config version 2.0
include menu.cfg
default vesamenu.c32
prompt 0
timeout 0
UI vesamenu.c32
MENU RESOLUTION 640 480
#MENU BACKGROUND
MENU COLOR border 30;44 #40dfdfdf #00000000 std
MENU COLOR title 1;36;43 #e0fdff49 #804206ef none
MENU COLOR sel 7;37;40 #e0000000 #40ffffff all
MENU COLOR hotsel 1;7;37;40 #e0af0000 #40ffffff all
MENU COLOR disabled 1;30;44 #ffe4de6f #00000000 std
MENU COLOR scrollbar 30;44 #40000000 #e0af0000 std
MENU TITLE Boot Menu
MENU CLEAR

MENU ROWS 14
MENU TABMSGROW 20
MENU CMDLINEROW 20
MENU TIMEOUTROW 22
MENU HELPMSGROW 24
MENU VSHIFT 1

MENU BEGIN debian_custom_install
MENU TITLE debian_custom

LABEL custom
KERNEL /install.amd/vmlinuz
APPEND video=vesa:ywrap,mtrr vga=788
initrd=/install.amd/initrd.gz debian-installer/locale=us_US debconf/priority=critical preseed/file=/options/preseed --

MENU SEPARATOR

LABEL exit0
MENU LABEL Return to the main menu
MENU EXIT

MENU END

No filesystem could mount root, tried:
Kernel Panic -not syncing: VFS: Unable to mount root fs on unknown-block(2,0)
Pid: 1, comm: swapper/0 Not tainted 3.2.0-4-amd64 #1 Debian 3.2.46.1
Call trace:
[ffffffff813481ed>] ? panic+0x95/0x1a2
[ffffffff816abf80>] ? mount_block_root+0x24e/0x27a


Obviously something went wrong :) I also tried to give initrd a root path (like root=/dev/rd/0 ) and to modify initrd archive as well with gzip and cpio, but it didn't work either . I would really appreciate if you could give me any clue how to solve this problem.

I think it is saying your kernel doesn't have built-in support for the CD filesystem. Remember that it can't load modules until the root filesystem is mounted. Check the config file for your kernel has CONFIG_ISO9660_FS=y (not m).

yes my kernel doesn't support iso9660
there was CONFIG_ISO9660_FS=m

I got kernel image and compiled it with CONFIG_ISO9660_FS=y, but i still dont know how to compile kernel inside initrd to run it on debian-installer, I run to some outdated info how to do a thing (it was about udeb )
should I chroot the initrd?..

a, and one more thing
the content of isolinux.cfg was made with a mistake,

APPEND video=vesa:ywrap,mtrr vga=788 initrd=/install.amd/initrd.gz debian-installer/locale=us_US debconf/priority=critical preseed/file=/options/preseed --

should be in one line ( I put a space) that is why I couldnt run debian-installer

now cd boots debian-installer also is running , but i get error

"incorrect cd detected"
the cd-rom contains a cd which cannot be used for installation ..etc.