[ovirt-users] storage allocation of template

Hello, I want to know whether a base disk image is physically copied whenever the VM is created from a template. I've just created a VM based on template with 1 disk and checked VM's virtual disk images. there were (1)base image copied? from the template, (2)new delta image. Here, (1) image was identical to that of the template and I know that image is used as read-only mode. So, I am wondering why base (disk) image is inefficiently copied instead of directly referencing template's image as backing file.