[libvirt] adding scsi disk failed (code=9)

Hi, I'm newbie and sorry if this question was already post in this ML (is there any search engine for the ML archive?). I'm trying to attach a volume in my instance. The instance is running and the volume is available, but i got this error: ---- libvirt: operation failed: adding scsi disk failed (code=9) virDomainAttachDevice() failed (err=-1) XML=<disk type='block'><driver name='phy'/><source dev='/dev/etherd/e0.8'/><target dev='sdb'/></disk> doAttachVolume() failed error=1 ---- I'm not sure where I can start to debug this error. I'm using Fedora 11, x86_64, with these packages [root@minicloud eucalyptus]# rpm -qa | grep libv libvirt-devel-0.6.2-12.fc11.x86_64 libvorbis-1.2.0-7.fc11.x86_64 libvirt-0.6.2-12.fc11.x86_64 libvirt-python-0.6.2-12.fc11.x86_64 libvolume_id-141-3.fc11.x86_64 May you help me, please? Thanks in advance, M