Thanks for the reply.
vCenter is a VM, with 8GB of RAM and 4 vCPUs assigned. It's vmdk lives on our fibrechannel SAN. Performance stats on that VM show no problems.
Our hosts are Dell PowerEdge R720s, two 8 core Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz, 128GB RAM, disk is fibre channel SAN
Our database server is a Sun/Oracle 890, 64GB RAM, disk via fiber channel. Runs Oracle 11g
Our SAN is an EMC (I don't know the model). But looking at performance stats we're only doing about 2k total IOs/sec, and average latency is around 5 milliseconds.