Kernel panic-not syncing:VFS:Unable to mount root fs on unknown-block(1,0) - RHEL 6.0
 

Hello everyone,

I am running RHEL 6.0 - 64bit
# uname -a
Linux redhat6 2.6.32-71.el6.x86_64 #1 SMP Wed Sep 1 01:33:01 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux

The issue I am having with my custom boot recovery media has only recently popped its ugly head with RHEL 6.0 This was not an issue with earlier releases of RHEL 5 and earlier.

Something has changed in RHEL 6.0 that is causing my custom cd to get a kernel panic during boot up.

Here is the message during boot up:

List of all partitions:
No filesystem could mound root, tried: iso9660
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(1,0)
Pid: 1, comm: swapper Not tainted 2.6.32-71.el6.x86_64 #1

Here are my files:




isolinux.cfg
---------------
default custom
display message
prompt 1
timeout 9000
say Press ENTER to continue booting to the Custom Recovery Menu
label custom
kernel vmlinuz
append initrd=custom.img ramdisk=92160 ramdisk_blocksize=1024 root=/dev/ram0



I believe the issue could possibly be in the way I am creating my custom.img
but I am not sure.

Please let me know what other information you require.
I am willing to pay anyone who provides an accurate solution.

Just a wild guess, but should'nt that be

Thor
(price : nothing)

I have tried other options to mounting root.

/dev/ram0 always worked in the past, which has the major minor of 1,0

# ls -l /dev/ram0
brw-rw----. 1 root disk 1, 0 Sep 22 11:37 ram0


I have tried setting root=/dev/dm-0

which in turn makes my kernel panic look like this:

List of all partitions:
No filesystem could mound root, tried: iso9660
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
Pid: 1, comm: swapper Not tainted 2.6.32-71.el6.x86_64 #1

Can we have a look at the /boot/grub/grub.conf file, please?

Absolutly, here it is:

# cat /boot/grub/grub.conf
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/mapper/vg_redhat6-lv_root
# initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux (2.6.32-71.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-71.el6.x86_64 ro root=/dev/mapper/vg_redhat6-lv_root rd_LVM_LV=vg_redhat6/lv_root rd_LVM_LV=vg_redhat6/lv_swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us crashkernel=auto rhgb quiet
initrd /initramfs-2.6.32-71.el6.x86_64.img

and

I dont get it...where does the (1,0) come from?

Lemme think...

Thor

It is coming from the menu.lst file




unknown-block(1,0) is referencing /dev/ram0

Yes, I know...just, how did it get from (0.0) in the grub to (1.0) afterwards...of course, you're booting a ram-residend file system, now it hits me.

Hmm...gotta think about that one...

I understand this is not a simple task.

I will appreciate any feedback.
Please let me know if you require any other information.

This is a task worth money to me for your time or anyone's time to resolve this issue.

Hmm, okay...maybe some ground rules. We dont take money, we're volunteers....but :) thanks anyway.
Oh and, by the way, I for one enjoy doing this...beats crosswords any time! :D

Did you tinker with the boot files? It's the ones in the list:

...

Hummm, not really sure,

I did a listing of files in /boot the end .b
Nothing came up.

[RHEL6.0 - 64bit] boot # ls -l *b
total 259
-rw-r--r--. 1 root root 63 Mar 10 2011 device.map
-rw-r--r--. 1 root root 13204 Mar 10 2011 e2fs_stage1_5
-rw-r--r--. 1 root root 12516 Mar 10 2011 fat_stage1_5
-rw-r--r--. 1 root root 11748 Mar 10 2011 ffs_stage1_5
-rw-------. 1 root root 841 Mar 10 2011 grub.conf
-rw-r--r--. 1 root root 11756 Mar 10 2011 iso9660_stage1_5
-rw-r--r--. 1 root root 13220 Mar 10 2011 jfs_stage1_5
lrwxrwxrwx. 1 root root 11 Mar 10 2011 menu.lst -> ./grub.conf
-rw-r--r--. 1 root root 11940 Mar 10 2011 minix_stage1_5
-rw-r--r--. 1 root root 14300 Mar 10 2011 reiserfs_stage1_5
-rw-r--r--. 1 root root 1341 May 6 2010 splash.xpm.gz
-rw-r--r--. 1 root root 512 Mar 10 2011 stage1
-rw-r--r--. 1 root root 113044 Mar 10 2011 stage2
-rw-r--r--. 1 root root 12008 Mar 10 2011 ufs2_stage1_5
-rw-r--r--. 1 root root 11364 Mar 10 2011 vstafs_stage1_5
-rw-r--r--. 1 root root 13932 Mar 10 2011 xfs_stage1_5


Now, all these files above I copy over into the custom boot directory, but I do not modify any of these files.

Hmm, not sure if that could be a snag...installing rarthere than copying should be the approach...

Wow, this is a riddle...

Just to recap (just woke up, here) you've got a file system in memory/on disk that should be boot up. I guess your "creation" lives in there...ever tried burning a CD rom or putting it on a USB stick? That way it would be the only FS on that device. I doubt werther booting (grub-wise) of an in-memory FS like that is possible...

Never saw that B4...

Thor

I am currently using a USB stick to do this on. That is my boot recovery media.
I have also tried using a CD. Both with the same error.

okay, so, you boot off the USB stick, I gather. What's the grub menu like over there?
I assume there is a grub on de USB stick as well...