Windows server 2008; no drives were found. clickload drivers

Trying to load Windows server 2008 from an iso on top of KVM. Got the error mesg

windows 2008 no drives were found. click load drivers to load mass storage driver for installation

My server is a Oracle/Sun X3-2 or 4170. We have loaded Nimbula ( an IaaS platform) which uses KVM hypervisor in the server. Trying to load Win2K8 on top of KVM. Mounted Sun ZFS storage as NFS and the iso sits there.

Have not tried virtio drivers yet.

What drivers do I need ?

Thanks

Nirlay