I have 12 new servers to deploy and want to use an exact copy of the existing 5.5 image on an existing host. What would be the best practice for this?
Stateful and stateless environment:
1. Keep your ISO in https location and setup the Scripted environment to boot all the host from the same ESXi ISO. All host boot with the same Build. VMware KB: Deploying ESXi 5.x using the Scripted Install feature
2. If you want the stateless environment then setup the auto deploy server in vCenter Server and Boot all host with the same auto deploy server keeping the same ISO. VMware KB: Understanding vSphere Auto Deploy Stateless Caching and Stateful Installs
Sorry for the last post i interpreted wrongly you need to use the same ISO to boot all the host. I dont have an idea that you fetch the image profile back from the host and create ISO.