[ovirt-users] Cannot export FC vms to NFS export

Hello, Since I cannot find a solution for my previous problem ( http://lists.ovirt.org/pipermail/users/2014-July/026255.html) I have decided to export all vms and start over. But when I clic to "export" I get the following message on every single vm (vms are off): *Cannot export VM. Disk configuration (COW Preallocated) is incompatible with the storage domain type.* The storage type is "Shared" Do I need to convert somehow the vms ? Thank you Fabien Carré