In a new whitepaper, a large installation of 16,000 Exchange users was configured across eight virtual machines (VMs) on a single VMware vSphere 4 server.  The storage used for the test was a NetApp FAS6030 array that supported Fibre Channel, iSCSI, and NFS storage protocols.  This allowed for a fair comparison of these three storage protocols on the same hardware.  The test results show that each protocol achieved great performance with Fibre Channel leading the way, and with iSCSI and NFS following closely behind.


Similar tests have been done to compare Fibre Channel, iSCSI, and NFS on ESX in the past.  These tests used IOmeter to measure the storage performance.  In this new round of tests, Exchange Load Generator was used as the test tool to simulate an 8-hour work day.


The results show that Fibre Channel provided the best performance with the lowest CPU utilization.  Additionally, iSCSI and NFS were relatively close in performance.  The two graphs below summarize the test results showing the sendmail average latency as reported by LoadGen and the overall CPU utilization of the the ESX server.






The complete whitepaper has all of the configuration details and additional test results.