We have a strange problem: On the top of each hour (7:00, 8:00, 9:00, etc) we get a iSCSI reset. I am working with Dell, EMC and VMware on this but still don't have an answer. The key issue seems to be a VMware Host is dropping connections when the latency builds up and then does a power on reset, which effects all hosts. I'm not sure why this happens at the top every hour as opposed to a random time. Once the reset happens within a minute everything is back to normal until the next hour. The EMC VNXe3200 does not report any errors only the VMware Hosts report errors and this happens on all 3 hosts at the same time.
iSCSI configuration: We have 3 Dell R630's running VMware ESXi 6.0 (2809209) which connects to an EMC VNXe 3200 (SP A/ SP B Active/Active) on two unique Dell 6224 (1 GB) switches. Each host has 2 connections on two different subnets to the SAN. MTU 1500. This is a separate iSCSI only network.
When the reset occurs, the system on the applications is one of network loss (Outlook can't connect, then connects OK).
We did have only 1 LUN configured though I'm in the process have adding more LUNs and distributing the VM's across them to help with I/O. It seems that some process must kick off at the top of each hour but I can't find it and all 3 vendors say they don't have any idea what it could be.
Any help would be much appreciated. - Thanks...