A customer has two identically configured Linux hosts (OS version, memory, CPU) attached to the same network. One host is NFS-attached and the other is FC-attached to an EMC VNX. Both the NFS file…

A customer has two identically configured Linux hosts (OS version, memory, CPU) attached to the same network. One host is NFS-attached and the other is FC-attached to an EMC VNX. Both the NFS file systems and the SAN LUNs are created from four RAID 5 (4+1) RAID groups. LUNs are not shared between file and block and each host generates the same size I/O. The customer reports the FC-attached host is able to achieve much greater throughput than the NFS-attached host. What is the source of the performance difference between the file and block configurations?