[ovirt-users] can't import vm from KVM host

Hello, I'm trying to import virtual machines from a KVM host (centos 7.2) to an oVirt 4.0.2 Cluster using the "import" feature on GUI. If the original VM is using RAW/QCOW2 files as storage, everything works fine. But if the original VM is using a special block special device as storage (like a LVM or SAN volume), it's simply not recognized. The VM does appear in the import list of the KVM host, but it's disk count is 0! Is this a known technical obstacle or am I doing something wrong ? below is the storage part of the xml describing the original VM : <disk type='block' device='disk'> <driver name='qemu' type='raw' cache='none' io='native'/> <source dev='/dev/mapper/vg_01-lv_sys'/> <target dev='vda' bus='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/> </disk> <disk type='block' device='disk'> <driver name='qemu' type='raw' cache='none' io='native'/> <source dev='/dev/sdc'/> <target dev='vdb' bus='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/> </disk> We have hundreds of virtual machines in production with this type of configuration... How can we migrate them safely to oVirt? thanks Nelson