can't boot after install

[ryadav]

I've installed xubuntu 10.10 on my PC, after installing I get a kernel panic.

I have the following partition layout

/dev/sda1 ( /boot )
/dev/sda5 ( swap )
/dev/sda6 ( / )

On bootup I see the grub 2 menu

The kernel panic message says - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

I can boot into my root filesystem on /dev/sda6 using the rescue mode and everything seem good

[Rubi1200]

Hi,
use a LiveCD/USB to boot the computer in live mode.

Then, post the results of the boot-script linked at the bottom of my post.

Hopefully, this will help us determine the source of your problem and make offering solutions easier.

Thanks.

[ryadav]

I am using the alternative CD to install from, all i have is the shell, i can't install using the LiveCD

i am guessing, but i think the /boot/grub/grub.cfg file is confused where to find root, how do i fix this manually? if I can get this system up and running I can provide the files you need to look at to correct future install, i make a copy before i edit.

FYI: i tried telnet or rsync from my other linux box, but i keep getting a connection refused error

[ryadav]

Here is my boot script info, why am I getting a kernel panic after a fresh install of Xubuntu 10.10? This message says:

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

Boot Info Script 0.55 dated February 15th, 2010

============================= Boot Info Summary: ==============================

=> Grub 2 is installed in the MBR of /dev/sda and looks on the same drive in
partition #1 for (,msdos1)/boot/grub.

sda1: __________________________________________________ _______________________

File system: ext4
Boot sector type: -
Boot sector info:
Operating System: Ubuntu 10.10
Boot files/dirs: /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img

sda2: __________________________________________________ _______________________

File system: Extended Partition
Boot sector type: Unknown
Boot sector info:

sda5: __________________________________________________ _______________________

File system: swap
Boot sector type: -
Boot sector info:

=========================== Drive/Partition Info: =============================

Drive: sda ___________________ __________________________________________________ ___

Disk /dev/sda: 30.8 GB, 30758289408 bytes
255 heads, 63 sectors/track, 3739 cylinders, total 60074784 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition Boot Start End Size Id System

/dev/sda1 * 2,048 59,887,615 59,885,568 83 Linux
/dev/sda2 59,889,662 60,073,983 184,322 5 Extended
/dev/sda5 59,889,664 60,073,983 184,320 82 Linux swap / Solaris


blkid -c /dev/null: __________________________________________________ __________

Device UUID TYPE LABEL

/dev/sda1 54f645ad-c340-4618-9657-39ceade647a7 ext4 root
/dev/sda2: PTTYPE="dos"
/dev/sda5 8a9cba64-836f-4bff-abc0-46d53200658d swap
/dev/sda: PTTYPE="dos"

============================ "mount | grep ^/dev output: ===========================

Device Mount_Point Type Options

/dev/sda1 / ext4 (rw,relatime,errors=remount-ro,barrier=1,data=ordered)
/dev/scd0 /media/cdrom iso9660 (ro,relatime)


=========================== sda1/boot/grub/grub.cfg: ===========================

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
set have_grubenv=true
load_env
fi
set default="0"
if [ "${prev_saved_entry}" ]; then
set saved_entry="${prev_saved_entry}"
save_env saved_entry
set prev_saved_entry=
save_env prev_saved_entry
set boot_once=true
fi

function savedefault {
if [ -z "${boot_once}" ]; then
saved_entry="${chosen}"
save_env saved_entry
fi
}

function recordfail {
set recordfail=1
if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}

function load_video {
insmod vbe
insmod vga
}

insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 54f645ad-c340-4618-9657-39ceade647a7
if loadfont /usr/share/grub/unicode.pf2 ; then
set gfxmode=640x480
load_video
insmod gfxterm
fi
terminal_output gfxterm
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 54f645ad-c340-4618-9657-39ceade647a7
set locale_dir=($root)/boot/grub/locale
set lang=C.UTF-8
insmod gettext
if [ "${recordfail}" = 1 ]; then
set timeout=-1
else
set timeout=10
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
menuentry 'Ubuntu, with Linux 2.6.35-22-generic' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 54f645ad-c340-4618-9657-39ceade647a7
linux /boot/vmlinuz-2.6.35-22-generic root=UUID=54f645ad-c340-4618-9657-39ceade647a7 ro quiet splash
initrd /boot/initrd.img-2.6.35-22-generic
}
menuentry 'Ubuntu, with Linux 2.6.35-22-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 54f645ad-c340-4618-9657-39ceade647a7
echo 'Loading Linux 2.6.35-22-generic ...'
linux /boot/vmlinuz-2.6.35-22-generic root=UUID=54f645ad-c340-4618-9657-39ceade647a7 ro single
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-2.6.35-22-generic
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 54f645ad-c340-4618-9657-39ceade647a7
linux16 /boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 54f645ad-c340-4618-9657-39ceade647a7
linux16 /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
if [ "x${timeout}" != "x-1" ]; then
if keystatus; then
if keystatus --shift; then
set timeout=-1
else
set timeout=0
fi
else
if sleep --interruptible 3 ; then
set timeout=0
fi
fi
fi
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f $prefix/custom.cfg ]; then
source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###

=============================== sda1/etc/fstab: ===============================

# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
# / was on /dev/sda1 during installation
UUID=54f645ad-c340-4618-9657-39ceade647a7 / ext4 errors=remount-ro 0 1
# swap was on /dev/sda5 during installation
UUID=8a9cba64-836f-4bff-abc0-46d53200658d none swap sw 0 0

=================== sda1: Location of files loaded by Grub: ===================


10.8GB: boot/grub/core.img
10.8GB: boot/grub/grub.cfg
.4GB: boot/initrd.img-2.6.35-22-generic
10.8GB: boot/vmlinuz-2.6.35-22-generic
.4GB: initrd.img
10.8GB: vmlinuz
=========================== Unknown MBRs/Boot Sectors/etc =======================

Unknown BootLoader on sda2

00000000 a4 ff 8b 54 24 54 89 14 24 ff d0 84 c0 74 b8 8b |...T$T..$....t..|
00000010 4c 24 78 8b 01 89 0c 24 ff 90 c8 00 00 00 8b 4c |L$x....$.......L|
00000020 24 70 8b 11 8b 4c 24 74 89 44 24 0c 8b 44 24 48 |$p...L$t.D$..D$H|
00000030 89 4c 24 04 89 44 24 08 8b 44 24 70 89 04 24 ff |.L$..D$..D$p..$.|
00000040 92 94 00 00 00 83 c4 5c 5b 5e 5f 5d c3 8b 54 24 |.......\[^_]..T$|
00000050 70 8b 02 89 14 24 ff 90 90 00 00 00 89 44 24 58 |p....$.......D$X|
00000060 e9 f9 fd ff ff 90 8d 76 00 8d bc 27 00 00 00 00 |.......v...'....|
00000070 83 ec 4c 89 74 24 40 8b 74 24 54 89 5c 24 3c 89 |..L.t$@.t$T.\$<.|
00000080 7c 24 44 89 6c 24 48 8b 06 e8 39 a9 a5 ff 81 c3 ||$D.l$H...9.....|
00000090 8e 39 74 00 89 34 24 ff 90 d8 05 00 00 89 44 24 |.9t..4$.......D$|
000000a0 34 8b 06 89 34 24 ff 90 e0 05 00 00 89 44 24 38 |4...4$.......D$8|
000000b0 8b 06 89 34 24 ff 90 e8 05 00 00 89 c5 8b 06 89 |...4$...........|
000000c0 34 24 ff 90 f0 05 00 00 89 c7 8b 06 89 34 24 ff |4$...........4$.|
000000d0 90 d0 05 00 00 89 7c 24 1c 89 6c 24 18 89 34 24 |......|$..l$..4$|
000000e0 89 44 24 2c 8b 44 24 6c 89 44 24 28 8b 44 24 68 |.D$,.D$l.D$(.D$h|
000000f0 89 44 24 24 8b 44 24 64 89 44 24 20 8b 44 24 38 |.D$$.D$d.D$ .D$8|
00000100 89 44 24 14 8b 44 24 34 89 44 24 10 8b 44 24 60 |.D$..D$4.D$..D$`|
00000110 89 44 24 0c 8b 44 24 5c 89 44 24 08 8b 44 24 58 |.D$..D$\.D$..D$X|
00000120 89 44 24 04 e8 7b 1c a5 ff 8b 5c 24 3c 8b 74 24 |.D$..{....\$<.t$|
00000130 40 8b 7c 24 44 8b 6c 24 48 83 c4 4c c3 90 66 90 |@.|$D.l$H..L..f.|
00000140 55 57 56 53 e8 7e a8 a5 ff 81 c3 d3 38 74 00 83 |UWVS.~......8t..|
00000150 ec 5c 8b 83 c0 c2 ff ff 89 04 24 e8 74 91 a3 ff |.\........$.t...|
00000160 8b b3 40 5f ff ff 89 34 24 e8 46 f0 a3 ff 89 44 |..@_...4$.F....D|
00000170 24 3c 89 04 24 e8 ca 83 a5 ff 89 34 24 e8 32 f0 |$<..$......4$.2.|
00000180 a3 ff 89 c5 89 04 24 e8 b8 83 a5 ff 8b 54 24 70 |......$......T$p|
00000190 8b 02 89 14 24 ff 90 bc 03 00 00 89 34 24 89 44 |....$.......4$.D|
000001a0 24 58 e8 0d f0 a3 ff 89 44 24 38 89 04 24 e8 91 |$X......D$8..$..|
000001b0 83 a5 ff 8b 4c 24 70 8b 01 89 0c 24 ff 50 00 fe |....L$p....$.P..|
000001c0 ff ff 82 fe ff ff 02 00 00 00 00 d0 02 00 00 00 |................|
000001d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.|
00000200

[dino99]

your kernel panic can be due to bad kernel compilation or driver(s) you need not compiled into kernel, but dont worry (have always kernel panic on first boot with my system)

add on the boot line (before: quiet splash), either: nomodeset, noapic, nolapic, noacpi, irqpoll

often noacpi does the trick

[ryadav]

how and where do i add the lines to test? the kernel panic is saying something specifically about VFS, it should be the same kernel image i am using during install which i believe is the same kernel when i boot into rescue mode off the install CD ?

[Rubi1200]

I don't see any obvious errors in the results of the boot-script.

So, as dino99 suggested, the cause may be elsewhere.

When the computer boots and you see the GRUB entry for Ubuntu hit "e" to edit the menu entry and then find the line that ends with
quiet splashYou can then add one of the parameters suggested by dino99 after quiet splash and hit "Ctrl" + "x" to boot.

For example,
quiet splash noacpiLet us know what happens.

[ryadav]

i've tired what dino99 suggested, i am still getting the same error

[ryadav]

i don't have this issue with debian 5.0, i only see this on ubuntu install, what does the kernel panic error mean, i've google and can't seem to figure it out??

not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

[Rubi1200]

There could be a number of possible causes and I am not sure if it is really worth taking the time to track it down.

I suggest you backup important data and go for a fresh install.