When I look at the performance metrics for the HP EVA, I do not see any latency counters.
vFoglight Storage does not currently display the latency for the HP EVAs. This is a known enhancement request for vFoglight Storage referenced by Quest Tracking ID 1243.
Enhancement request 1243 has been submitted to Development for a fix in a future release. Please check the release notes of latest software to determine which enhancements and bug fixes have been included in this release.
vFoglight Storage version 1.6