I was reading up on Oracle RAC 11g Cluster and come across Direct NFS Client from Oracle.
Decreasing prices, simplicity, flexibility, and high availability are driving the adoption of Network-Attached Storage (NAS) devices in enterprise data centers. However, performance and management limitations in the Network File System (NFS) protocol, the de facto protocol for NAS devices, limits its effectiveness for database workloads.Oracle Direct NFS Client, a new feature in Oracle Database 11g, integrates the NFS client directly with the Oracle software. Through this tight integration, Direct NFS Client overcomes the problems associated with traditional operating system kernel based NFS clients.Direct NFS Client simplifies management by providing a standard configuration within a unified interface across various hardware and operating system platforms. The tight integration between Direct NFS Client and the Oracle database vastly improves I/O performance and throughput, while reducing system resource utilization.Finally, Direct NFS Client optimizes multiple network paths to not only provide high availability but to achieve near linear scalability by load balancing I/O across all available storage paths.
I personally do not think there are many customers using Direct NFS Client. If I can afford Oracle Database license, I would not even bother about getting a cheaper alternative to a SAN.