We have been running some tests in our environment with less than ideal results. Our environment consists of 6 vSphere4 hosts in one cluster connected to about 10 VMFS volumes. Each host has a dedicated vSwitch with two pNICs, 3 vmkernel ports per NIC, and each NIC is connected to a different physical switch. We have set the path policy to Round Robin so each volume has 6 active paths listed. On the EqualLogic side, we have 3 members in a group, one pool for that group, and the controllers are connected to / balanced across those same two physical switches (Nexus 5020). This was based off the guide from the EqualLogic site. http://www.equallogic.com/resourcecenter/assetview.aspx?id=8453
Our issue is when we try to test failover / availability by simulating a switch outage. The EqualLogic group sees numerous timeouts / login errors, but still has NICs active on the active controller, so there is no controller failover. The hosts lose one of the two NICs on the storage vSwitch, but even with one NIC up and online all VMFS volumes disappear from every host. When we bring the switch back online, all the VMFS volumes come back without taking any corrective measures, and the VMs appear as if nothing has happened. Trying to use the VMs we see performance degradation until we rescan / clean up the storage communication and then everything returns to normal.
We're at a loss on where to begin. We have followed the recommendations from EqualLogic and of course being the VMware guy I'm pointing at the storage. The hosts still show active paths when this happens and the errors are login timeouts which is the other reason I think it would be good to start at the storage side. Anyone out there with similar configurations who may have run into something similar?
