How to use the same physical NIC ports as iSCSI for VirtuCache replication, since those are the only 10gbps ports on our hosts
Question: We are planning to run VirtuCache in ‘Write-Back 1 Replica’ mode, but the only two 10g NIC ports we have on each host are used for iSCSI. Rest of the ports on the host are 1g . We obviously want to use the two 10g ports in a teamed config for VirtuCache write replication. Now in each VMware host the vSwitch for iSCSI is configured to use two vmkernel adapters, each using a different IP address. So iSCSI-A uses vmk0 as active and vmk1 as standby, and iSCSI-B uses vmk1 as active and vmk0 as standby. Now how do we configure the write replication network in a HA/teamed configuration on the same vSwitch and using the same two 10g NIC ports.
Answer : You create another vmkernel adapter for VirtuCache write replication running on the same vswitch, and hence using the same two physical 10gbps NIC ports, but this vmkernel adapter will have these NIC ports in a teamed configuration. You can choose these two ports to be in Active-Active or Active Standby. Now you have the same two NIC ports that you are using for iSCSI, also being used for VirtuCache write replication, only with VirtuCache write replication, these two NIC ports are teamed and using a single IP address. Now if one port fails either on the host or the switch, then the VirtuCache write replication traffic will go over the other NIC port and the other switch port.
To isolate the iSCSI traffic from VirtuCache write replication you should create a separate VLAN.
This config will work fine if the storage traffic is less than 10gbps and the iSCSI + VirtuCache write replication traffic is less than 20gbps.