[libvirt] libvirtd hang while saving domain ??

Hi, if i save a kvm domain, libvirt will not answer to any command (e.g. virsh list). While saving, the dd process works ... after finishing, it possible to execute virsh commands. Why does libvirtd blocks ? Is there a way to process the requests in concurrency ? 25766 ? S 0:00 sh -c dd of='/tmp/storage11.POOL401-w2-VM323.suspendRAM' oflag=append conv=notrunc 2>/dev/null 25767 ? D 0:03 dd of /tmp/storage11.suspendRAM oflag append conv notrunc regards Danny