[one-users] Problems with qcow2 images

[Alexander Fedulov]

I created a qcow2 image from a raw image like this:
> qemu-img create -f qcow2 -b ubuntu10-04.img qcow.img

The DISC section of of my deployment descriptor looks like this:
> DISK   = [
>   source   = "/srv/cloud/temp/ubuntu10-04/qcow.img",
>   target   = "sda",
>   readonly = "no" ,
>   DRIVER = qcow2]

I have edited the ~/lib/tm_commands/nfs/th_clone.sh file according to 
this https://support.opennebula.pro/entries/348847-using-qcow-images 
without the SSH part:

> *)
>     log "Cloning $SRC_PATH"
>     exec_and_log "qemu-img create -f qcow2 -o backing_file=$SRC_PATH 
> $DST_PATH"
>     ;;
> esac

Unfortunately deployment fails and this is what I find in the one-*.log 
files in the /var/log/libvirt/qemu folder of a target host.

> LC_ALL=C 
> PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin 
> QEMU_AUDIO_DRV=none /usr/bin/kvm -S -M pc-0.12 -enable-kvm -m 768 -smp 
> 1 -name one-24 -uuid 9f3d9ed7-d17f-e6d1-d997-5fed5a84aa47 -chardev 
> socket,id=monitor,path=/var/lib/libvirt/qemu/one-24.monitor,server,nowait 
> -monitor chardev:monitor -no-acpi -boot c -drive 
> file=/srv/cloud/one/var//24/images/disk.0,if=scsi,index=0,boot=on,format=qcow2 
> -drive 
> file=/srv/cloud/one/var//24/images/disk.1,if=scsi,media=cdrom,index=2,format=raw 
> -net nic,macaddr=02:00:c0:a8:90:22,vlan=0,name=nic.0 -net 
> tap,fd=54,vlan=0,name=tap.0 -serial none -parallel none -usb -vnc 
> 0.0.0.0:20 -k de -vga cirrus
> qemu: could not open disk image /srv/cloud/one/var//24/images/disk.0: 
> Permission denied
Deployment of raw images works fine. The version of ON is 2.0.1.

I was wondering, whether there is some chmod operation that has to be 
added to the tm_clone.sh script or is the problem in something else?