[Qemu-discuss] troubleshoot vm start up and raw disk format

[sho]

hypervisor - ubuntu natty 2.6.38-13-server #57-Ubuntu SMP Mon Mar 5
19:52:44 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

a VM, also ubuntu based, was hanging on vm initiated reboot, without
any useful error messages.
virsh destroyed the domain, killed -9 the remaining process and can
not start up the vm now.
hangs at "Booting from Hard Disk" message.

the fs is active-active-drbd/ocfs2, in sync and clean, other VMs are
running in on the same fs.

tried copying the image to local disk and another system and had the
same issue starting up the vm.

libvirt debug 1 output doesn't show anything useful.

qemu-img doesn't seem to support any checking of raw disk format,
which is what we use as the default in all vms.

package info

ii  kvm
1:84+dfsg-0ubuntu16+0.14.0+noroms+0ubuntu4.5 dummy transitional
package from kvm to qemu-kvm
ii  qemu                            0.14.0+noroms-0ubuntu4.5
         dummy transitional package from qemu to qemu-kvm
ii  qemu-kvm                        0.14.0+noroms-0ubuntu4.5
         Full virtualization on i386 and amd64 hardware

full args

106      29758     1 99 12:53 ?        00:26:00 /usr/bin/kvm -S -M
pc-0.14 -enable-kvm -m 2048 -smp 2,sockets=2,cores=1,threads=1 -name
gal1 -uuid d93123c4-8d38-d4f8-6f92-9a9fcaa81efa -nodefconfig
-nodefaults -chardev
socket,id=charmonitor,path=/var/lib/libvirt/qemu/gal1.monitor,server,nowait
-mon chardev=charmonitor,id=monitor,mode=readline -rtc base=utc -boot
order=c,menu=off -drive
file=/data/vm1/gal1.img,if=none,id=drive-virtio-disk0,boot=on,format=raw
-device 
virtio-blk-pci,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0
-drive file=/data/vm1/gal1-data.img,if=none,id=drive-virtio-disk1,format=raw
-device 
virtio-blk-pci,bus=pci.0,addr=0x7,drive=drive-virtio-disk1,id=virtio-disk1
-netdev tap,fd=21,id=hostnet0 -device
virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:10:ce:70,bus=pci.0,addr=0x3
-chardev pty,id=charserial0 -device
isa-serial,chardev=charserial0,id=serial0 -usb -vnc 127.0.0.1:1 -vga
cirrus -device AC97,id=sound0,bus=pci.0,addr=0x4 -device
virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6
root     31431 9211 0 13:19 pts/4    00:00:00 grep --color=auto gal1

any ideas ?

thanks a lot in advance !