The other important aspect for setting up an Infrastructure as a Service is shared storage. Virtual servers inside the server pool use shared storage mounted on external storage servers, filesystems, or LUNs. These external storage servers are available for the virtual servers via fiber channels or network communication over Ethernet.
Oracle VM Manager makes use of both standard and vendor-specific plugins to support almost all flavors of storage:
Local Storage: This uses the local hard disks on Oracle VM Servers. This option is not used on most real-life use cases. When the topology becomes more complex and you start thinking about HA (high availability), using replication and clustering, you will immediately realize the limitations of local storage for VMs.
Network Attached Storage (NAS): This is typically on NFS. Network file system (NFS) is an industry standard filesystem and can allow shared storage to VMs inside the server pool. NFS allows for flexible clustering...