VirtualBox in Knoppix 7.0.5 can't run rhel_6.0 x86_64 iso

[rajibando]

Just as I have said, VirtualBox in Knoppix 7.0.5 can't run rhel_6.0 x86_64 iso. It stops with message:

This kernel requires an x86-64 CPU, but only detected an i686 CPU. Unable to boot - please use a kernel appropriate for your CPU.
Now, I have a x86-64 CPU as the hardinfo report states. But still, the problem in identification. Is there anything wrong with the kernel? The same message appears in Knoppix VirtualBox.
The same happens with Squeeze 6.0.3, and I have posted the same message with appropriate changes in the Debian Forum, with the subject, VirtualBox in Squeeze 6.0.3 can't run rhel_6.0 x86_64 iso (http://forums.debian.net/viewtopic.php?f=5&t=103157&p=493040#p493040)

Regards

[Capricorny]

.....
Now, I have a x86-64 CPU as the hardinfo report states. But still, the problem in identification. Is there anything wrong with the kernel? The same message appears in Knoppix VirtualBox.
The same happens with Squeeze 6.0.3, and I have posted the same message with appropriate changes in the Debian Forum, with the subject, VirtualBox in Squeeze 6.0.3 can't run rhel_6.0 x86_64 iso (http://forums.debian.net/viewtopic.php?f=5&t=103157&p=493040#p493040)
.....


Knoppix is a 32-bits Linux distro, using 64-bits kernel as an option. Most virtualization software needs a full 64-bits host system to run 64-bits guests (including Knoppix with 64-bits kernel :) ) . To achieve this with Knoppix, there are two ways that I know of, and have used:
1) Create a pure 64-bits version.
2) Chroot into a minimal 64-bits install and run virtualization software there.

I wouldn't try #1 with Knoppix 7.0.5. But #2 has been quite useful.
I haven't tried with Virtualbox, but qemu/kvm and vmware workstationhave both worked this way for me. If you have tried and run into problems with 64-bits Squeeze 6.0.3, it may have other reasons.

[rajibando]

I have a minor reading disability which hinders me from reading too much and using Character User Interface rather than Graphical User Interface.
What is chroot? I googled and found these two pages:
(1) http://www.linuxquestions.org/questions/linux-general-1/how-to-use-knoppix-as-a-chroot-754883/
(2) http://bhavesh.freeshell.org/blog/linux/909090.html
Didn't understand beyond a point.
Wikipedia says:
After mounting the live CD's filesystem, software on the live CD can be run directly (I.e., without booting) by chrooting (http://en.wikipedia.org/wiki/Chroot) into the live CD's mounted filesystem
Then I read chroot from wikipedia, and that's about it. Then, catch22 situation.
I am also a bit dumb :) because I can't understand apparently simple explanations.
Regards

[Capricorny]

Chroot means that you use another directory than / for root directory. Which in effect implies (among other things) that you will use all the system routines, libraries etc in the new directory structure rather than the original ones. If you think this may be problematic, you are quite right. If, however, the new routines are compatible with the host system, like substituting 64-bits libraries for 32-bits when the kernel runs 64 bits anyway, as with Knoppix, things may work out quite well.

I have written about it in this thread:
http://knoppix.net/forum/threads/29961-How-to-get-64-bits-qemu-running-in-Knoppix-7.X

It worked for me then, but I haven't tested it thoroughly.

[rajibando]

Dear Capricorny,
I have observed that you are very patient, especially with people fidgety like I am. Thank you. The <a href ="http://knopper.net/knoppix/knoppix705-en.html"> Knoppix 7.0.5 </a> page contains the above subject line. Please guide. I regularly (nearly exclusively) use cloop with Knoppix to get all my work done.
The cloop line in my grub menu is:


menuentry "Knoppix cloop" {
echo 1
echo 2
linux (hd0,x)/boot/isolinux/linux root=/dev/ram rw ramdisk_size=100000 lang=us apm=power-off nomce xmodule=fbdev tz=/Asia/Kolkata
echo 3
initrd (hd0,x)/boot/isolinux/minirt.gz
My question is: Where do I write "knoppix64" ?

[Capricorny]

Here are the two entries in legacy grub's menu.lst I use for the versien I am currently running:


title Knoppix 7.0.5r2 64 bits DVD cloop version sda2
kernel (hd0,2)/boot/knx705/linux64 fromhd=/dev/sda2 knoppix_dir=KNOPPIX705_clr2 nosound keyboard=no ramdisk_size=100000 lang=no apm=power-off initrd=minirt.gz nomce libata.force=noncq hpsa.hpsa_allow_any=1 loglevel=1 tz=localtime
initrd (hd0,2)/boot/knx705/minirt.gz

title Knoppix 7.0.5r2 32 bits DVD cloop version sda2
kernel (hd0,2)/boot/knx705/linux fromhd=/dev/sda2 knoppix_dir=KNOPPIX705_clr2 nosound keyboard=no ramdisk_size=100000 lang=no apm=power-off initrd=minirt.gz nomce libata.force=noncq hpsa.hpsa_allow_any=1 loglevel=1 tz=localtime
initrd (hd0,2)/boot/knx705/minirt.gz
To get 64-bits kernel, I use the linux64 kernel.

The most important other options used here:

* Booting from a separate partition that is nomally not mounted (/dev/sda3 = (hd0,2) for legacy grub )
* Using a separate boot subdirectory (/media/sda3/boot/knx705) for the Knoppix 705 files
* Using the main Windows partition for Knoppix system (/dev/sda2)
* Using KNOPPIX705_clr2 as Knoppix-dir instead of KNOPPIX (Denotes cloop remastering #2 of 7.0.5)

For experimentation, entries for other Knoppix subdirectories, other kernels other minirt versions etc can be added.

How to work with other bootloaders - i don't exactly know.

[rajibando]

Ah!... Now I got it, it's Linux64, not Knoppix64! Really, highly knowledgeable people don't tend to go back to what they have written! And mere mortals like us die of choking in the water bucket!

[Capricorny]

Ah!... Now I got it, it's Linux64, not Knoppix64! Really, highly knowledgeable people don't tend to go back to what they have written! And mere mortals like us die of choking in the water bucket!

Yes, it can be really confusing - knoppix64 is the name of a standard option in the default CD/DVD/USB booting of Knoppix. Those options can be edited/added in "micro-remastering". Using grub, we refer to the actual booting files. (I think that applies for all grubs, but I only use legacy so far.) Good luck :)

[rajibando]

The following link explains the reason why the emulation does not happen, thanks to able and patieint guidance by the Debian forum members pdespite my dumbheadedness. http://forums.debian.net/viewtopic.php?f=5&t=103157&start=1