I have an nexenta iscsi array and I just purchased a Qnap array to back up the nexenta, is it possible to have Vmware mirror the new qnap with the vm's on the nexenta?
You can use vSphere Replication to create replicas of VMs running on Nexenta, take a look on vSphere Replication FAQ: VMware KB: vSphere Replication FAQ
Yes, Use VMware Site recovery manager to do it.
Take a look at this whitepaper