[Qemu-devel] ask about simulating cluster using Qemu

[Qemu-devel] ask about simulating cluster using Qemu

[Mulyadi Santosa]

Hello all

I have been following Qemu's development for about 3-4 months and I must say :
TOTALLY AWESOME !!

OK, to the point, i want to ask several things:
1. I have plan to simulate openMosix cluster....just 2 node for start. 1 node 
is my real PC, and the other is Qemu emulated host. AFAIK, when I try to load 
openMosix patched kernel (using 0.5.2), it got some errors on initial kernel 
loading......sorry I lost the exact message

What should I do to solve it, at least clues to debug it....?

2. should I use tmpfs mounted on /tmp to accelerate Qemu? User Mode Linux 
suggest to use tmpfs....does Qemu use same method?

3. Is there any automation tools for generating disk image, more or less 
similar with UMLBuilder for UML? So far, for creating one, I put Debian Woody 
CDROM, boot it inside Qemu and install it into pre-made empty file.....

4. at certain interval, i got this message when running Debian:
"probable hardware bug: restoring chip configuration
probable hardware bug: clock 	timer configuration lost - probably  a VIA686a
probable hardware bug: restoring  chip configuration"

What does it mean?

Thanks and regards

Mulyadi

Re: [Qemu-devel] ask about simulating cluster using Qemu

[Fabrice Bellard]

Mulyadi Santosa wrote:
> Hello all
> 
> I have been following Qemu's development for about 3-4 months and I must say :
> TOTALLY AWESOME !!
> 
> OK, to the point, i want to ask several things:
> 1. I have plan to simulate openMosix cluster....just 2 node for start. 1 node 
> is my real PC, and the other is Qemu emulated host. AFAIK, when I try to load 
> openMosix patched kernel (using 0.5.2), it got some errors on initial kernel 
> loading......sorry I lost the exact message
> 
> What should I do to solve it, at least clues to debug it....?
> 
> 2. should I use tmpfs mounted on /tmp to accelerate Qemu? User Mode Linux 
> suggest to use tmpfs....does Qemu use same method?

Yes, but it matters only for qemu-fast.

> 3. Is there any automation tools for generating disk image, more or less 
> similar with UMLBuilder for UML? So far, for creating one, I put Debian Woody 
> CDROM, boot it inside Qemu and install it into pre-made empty file.....

No. But you can use tools from other projects.

> 4. at certain interval, i got this message when running Debian:
> "probable hardware bug: restoring chip configuration
> probable hardware bug: clock 	timer configuration lost - probably  a VIA686a
> probable hardware bug: restoring  chip configuration"

It is a QEMU bug :-)

Fabrice.

Re: Re: [Qemu-devel] ask about simulating cluster using Qemu

[Mulyadi Santosa]

hello :-)

> Yes, but it matters only for qemu-fast.
Is qemu-fast capable of loading kernel bzImage? Yesterday I did like this:
/usr/local/qemu/bin/qemu -kernel /boot/openmosix/bzImage -hda /mnt/myimage 
-append "root=/dev/hda1" -m 64  --> success

but when I did

/usr/local/qemu/bin/qemu-fast -kernel /boot/openmosix/bzImage -hda 
/mnt/myimage -append "root=/dev/hda1" -m 64

it hung with latest message:
Kernel panic : VFS : Unable to mount root fs on 03:01

Do I need to tweak somewhere inside the kernel source or my disk image to get 
it running?

> No. But you can use tools from other projects.

But...still, I need to create raw disk image right? 

AFAIK UML use preformated ext2/ext3 (whatever the loaded kernel 
support).....sorry, I don't mean to rudely compare UML and QEMU, it just me 
that try to learn about QEMU....

> It is a QEMU bug :-)

Ehm...how can I help to trace (or maybe fix ) this bug? Any clue?

regards

Mulyadi