Backup, the protection of virtual machines (VMs) in a virtualized environment like VMware or any hypervisor, is often an afterthought. The initial focus is on migrating physical systems to the virtual environment and creating new VMs to host new applications. Initial backups tend to leverage the existing backup methodology, typically a backup agent is installed in the guest OS. Over time though, most virtualized environments gravitate to a virtualization specific backup application and these applications all count on disk as the primary target for backup and that is where the problems begin.