I have a 2 node Windows 2008R2 cluster connected to a 3PAR running SQL 2008 R2 Server. We had a hardware failure on a node 1 which cluster failed SQL server properly over to node 2. However, while running on node 2, we noticed there were disk IO issues. After node 1 was repaired, we return SQL to node 1 and rebooted node 2. Afterward, I allocated a volume from 3PAR (created the same as the production volumes) and ran SQLIO and strangely, node 2 no longer was having disk IO issues.
I verified MPIO are set to round robin for all volumes. MPclaim -v confirmed this. All HBAs are online and free from any errors via San Surf.
The 3PAR is 100% dedicated to this SQL cluster; there are no other hosts on the FC switches.
Any suggestions on how to troubleshoot this would be extremely helpful because my mind is drawing a blank.