Kernel panic: VFS: Unable to mount root fs on ram3

[SiKing]

I am trying to GRUB a Knoppix iso from the hard drive.

From the Knoppix mirror in /knoppix/contrib/grubboot.zip/boot/grub/menu.lst
I found:

# boot a KNOPPIX iso file
# /KNOPPIX/KNOPPIX on hda1
# with custom cheatcodes
# with the kernel vmlinuz and the
# initrd miniroot.gz extracted from
# boot.img from the Knoppix CD
# to /KNOPPIX/
# this example hda1 can also be a fat(32) filesystem
title "Knoppix-iso custom"
kernel (hd0,0)/knoppix/vmlinuz noddc depth=24 screen=1024x768 vsync=85
initrd (hd0,0)/knoppix/miniroot.gz

Using files from a Knoppix 3.4 CD, I tried:

title Knoppix - ISO at (hd0,0)
kernel (hd0,0)/boot/knoppix/linux26 bootfrom=/dev/hda1/boot/knoppix/KNOPPIX
initrd (hd0,0)/boot/knoppix/minirt26.gz
In my case, (hd0) is an NTFS (Windows XP) system. Unfortunately, the kernel crashes with
Kernel panic: VFS: Unable to mount root fs on ram3, and then Knoppix starts booting up but almost right away crashes with
Can't find KNOPPIX filesystem, sorry and I get dropped to a "limited shell." Dropping the bootfrom cheatcode, or using linux24 from the same CD, does not change anything. I also tried various no* cheatcodes, all with the same result.

Hardware is "standard" Fujistsu-Siemens Lifebook C1110 (http://www.fujitsu-siemens.com/products/mobile/notebooks/lifebook_c.html).

Am I totally out to lunch with this method? Anyone got this to work? Anything else that I can provide? Any help would be greatly appreciated.

[eon]

I haven't tried to boot an .iso image from HD but for what it's worth it seems like there are boot mangers
out there that can do this. Try http://btmgr.sourceforge.net/about.html or maybe: http://gujin.sourceforge.net/
Good luck

[SiKing]

On my machine I cannot boot from a floppy, but thanx for the suggestion.

While Googling for this error, I read somewhere that the kernel might not have compiled support for the file system in question. Since Knoppix runs from a ram disk, I think this is the wrong direction.

Am I doing something that is obviously way incorrect?

TIA to anyone with any suggestions.

[SiKing]

On the advice of someone, I tried using

kernel (hd0,0)/boot/knoppix/linux26 root=/dev/ram[0|1|2]
and I end up with the same error, just on a different ram disk.

Any help?

[SiKing]

If anybody is reading this :? I solved my problem (kudos to JS):
I was able to GRUB the kernel from an NTFS partition, because GRUB has native support for NTFS. However, the Linux kernel (provided with Knoppix 3.4) itself does not have native supports for NTFS, and therefore could not find the inird file ... which resulted in the above mentioned error.
After placing, the kernel, initrd file, and the image all on a FAT[16|32] partition, everything works just fine. :oops:

[SiKing]

For the sake of "generations to come". This "problem" can be considered a duplicate of something that has already been discussed a long time ago. I just should have done better reserch. The link is here:
http://www.knoppix.net/forum/viewtopic.php?p=52847