[libvirt-users] Issues after migrating from Xen to KVM

[Chris Lalancette]

On 05/01/2010 02:56 PM, Ralf Hornik Mailings wrote:
> Dear list,
> 
> I have moved my HVMs from xen to kvm and it worked well except some
> problems using virsh.
> 
> First, one OpenSolaris HVM does boot with warnings:
> 
> WARNING: /pci at 0,0/pci1af4,1100 at 1,2 (uhci1): No SOF interrupts have been
> received, this USB UHCI host controller is unusable*
> 
> *The corresponding process:
> 
> /usr/bin/qemu-system-x86_64 -S -M pc-0.12 -enable-kvm -m 1024 -smp
> 1,sockets=1,cores=1,threads=1 \
>                                              -name server01 -uuid
> e382c360-23bd-b400-0b89-9a1e69613ec4 -nographic \
>                                              -nodefaults -chardev
> socket,id=monitor,path=/usr/local/libvirt/var/lib/libvirt/qemu/server01.monitor,server,nowait
> \
>                                              -mon
> chardev=monitor,mode=readline -rtc base=utc -boot c -drive
> file=/dev/xen_vol/xen_opensol,if=none,id=drive-ide0-0-0,boot=on \
>                                              -device
> ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 -drive
> file=/dev/hde,if=none,id=drive-ide0-0-1 \
>                                              -device
> ide-drive,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 -device
> rtl8139,vlan=0,id=net0,mac=00:16:3e:28:85:7a,bus=pci.0,addr=0x4 \
>                                              -net
> tap,ifname=tap0,vlan=0,name=hostnet0 -chardev pty,id=serial0 -device
> isa-serial,chardev=serial0 -usb -device
> virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
> 
> This does not happen when I boot with plain qemu-bin:
> 
> /usr/local/kvm/bin/qemu-system-x86_64 -hda /dev/xen_vol/xen_opensol \
>                                                              -hdb
> /dev/hde -net nic,macaddr=00:16:3e:28:85:7a \
>                                                              -net
> tap,ifname=tap0 -nographic \
>                                                              -m 1024
> -daemonize
> 
> Second is one Centos 5.2 HVM that does not boot at all.
> However when I boot manually and omitt "-S" and "-nodefaults" then it
> comes up.
> 
> I looked for the -S option and I wonder why it is being used by default.
> Can anybody help me? I cannot see any further documentation about the
> "-nodefault" option and how to disable "-S"

The -S means "start suspended".  That's so that libvirt can fork off the
qemu process, do a bit of work, and then run the virtual machine.  In
general you can't remove it from the command-line libvirt generates, since
libvirt depends on it.

Also, with recent qemu, you don't really want to remove the -nodefaults either,
since it's another new feature that libvirt is coming to rely on.  The reasons
for using it are many, but basically it says not to create any devices by
default, but let the user specify all of them on the command-line.

What's the actual problem you are having with the CentOS guest?  What kind of
error messages do you see?

-- 
Chris Lalancette