[Users] Some naive questions on ovirt...

Hi All, I have few naive Qs for getting some understanding on how things are not working in my setup. I have a very very basic/simple setup.. 1 box hosting ovirt-engine and 1 host running f16, which is discovered and being managed by the ovirt. I don't have the luxury (atleast currently) to have a shared san/nas storage setup, so with help on irc, i configured and setup local dc with local cluster and added host to the local cluster. Now i am in the process of adding a virtual disk to my VM which i created using ovirt. 1) The virtual disk ovirt helps create, is a disk with all zeroes... so even if i am able to create the vdisk and attach it to the VM, when i start vm, obviously it won't boot, as the boot disk is not found. How do i let the ovirt use a existing .img image file which already has a os and root fs installed ( i have it from my virt-manager setup). ? I tried creatign a new storage domain of type iso, but not sure how to add my .img for oivrt to see/recognize and allow me to select that while creating a new VM ? Again, this is all local, so i created /iso/images and /data/images directory on my host, and tried keeping my .imgs there, but it does not work. 2) Is thin provisioning supported with just 1 host in the dc/cluster ? From vdsm_storage pdf i found on the wiki, there is a diagram which uses 2 hosts to do the thin provisioning... so are 2 hosts a must ? Also it talks abt mailbox LV, where the msgs are sent and recd between vdsm and spm to do the lvextend operation.. i am not clear on where physically this LV resides ? on host 1, host 2 or somewhere else ? Assuming its shared storage, does it mean that i cannot do thin prov, with local storage, as is the setup in my case ? thanx, deepak