libvirt users - Oct 2012 - What to configure for a guest with 2.2. kernel ...

Greetings, libvirt-users ...

I ask for help with virtualizing an ancient machine with a linux kernel 2.2.

I already succeeded doing that but I face random performance issues and
I somehow get lost in all the settings and options.

I am using Virtual Machine Manager:

* I can't chose something like Linux for the OS and 2.2 for the kernel.

Does the combination "linux/2.4 kernel" work or should I choose
"Other"
or "Generic" ?

* Later there I get a choice of "Architektur" (or
"architecture" ?
german here): for a 32bit-guest, should it be "i686" to reflect the
environment for the guest or "x86_64" to fully use the potential of
the
host?

Please forgive my questions, maybe they are FAQ somewhere, I really
fiddled a lot already ...

Thanks, Stefan

On 10/08/2012 03:13 PM, Stefan G. Weichinger wrote:
> 
> Greetings, libvirt-users ...
> 
> I ask for help with virtualizing an ancient machine with a linux kernel
2.2.
> 
> I already succeeded doing that but I face random performance issues and
> I somehow get lost in all the settings and options.
> 
> I am using Virtual Machine Manager:
> 
> * I can't chose something like Linux for the OS and 2.2 for the kernel.
> 
> Does the combination "linux/2.4 kernel" work or should I choose
"Other"
> or "Generic" ?
This is a question for virt-manager, which is a package built on top of
libvirt, and maintained on the virt-tools-list at redhat.com [cc'd, in case
someone wants to add more details to this thread].  That said, my
understanding is that the only use virt-manager makes of these
designations is knowing in advance whether your guest is able to support
virtio out of the box (newer Linux builds do, older ones don't), to know
whether to expose the disk image to the guest as virtio (faster) or as
scsi (slower, but portable to more guests).  Choosing other/generic is
always safe, if you later want to tweak things to see if virtio was
supported after all.
> 
> * Later there I get a choice of "Architektur" (or
"architecture" ?
> german here): for a 32bit-guest, should it be "i686" to reflect
the
> environment for the guest or "x86_64" to fully use the potential
of the
> host?
For running a 32-bit guest, either mode works (you can ALWAYS run a
32-bit OS on 64-bit hardware); the difference is that 64-bit mode gets
slightly more testing, but 32-bit mode is slightly more efficient as it
does not have to emulate instructions for 64-bit operations that will
not be used by your 32-bit guest.

-- 
Eric Blake   eblake at redhat.com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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Am 08.10.2012 23:13, schrieb Stefan G. Weichinger:
> 
> Greetings, libvirt-users ...
> 
> I ask for help with virtualizing an ancient machine with a linux kernel
2.2.
forgot to mention:

using qemu-kvm-1.1.1 on a 64bit gentoo host.

libvirt-0.9.13 now, downgraded from 0.10.2 today due to searching for a
solution (0.9 is stable in gentoo-terms, 0.10.x not yet)

The disks are stored as raw ... in LVM-volumes.

The symptoms:

sometimes the performance ist great, then lousy.
One window in the guest works fine, while another is completely
unresponsive.

I had it working well once .. then ruined it by wanting to optimize it.
Something around choosing the CPU for the virtual machine.

I assume I should use kvm32?

The machine to be virtualized originated on a pentium1 ... and runs fine
on a VMware-server-2.x ... but the vmware-server is old now as well ...

thanks in advance, Stefan