We have ESXi6.0 U2 and ESXi 6.5 connecting VNX 5400. We are using software iSCSI initiator no port-binding is being used. On the storage, we use Round-Robin policy. There are four paths from ESXi host to the storage. On the ESXi6.5, I see two paths as “Active I/O” and other two paths as “Active” to LUNs. The “Active I/O” paths going to SP which owns the LUN. My understanding is that “Active I/O” is the optimized path and it is being used for I/O activities, and the “Active” is standby path. We have another VNX on a separate site with ESXi 6.0, it shows all paths as “Active”, and I do not see any “Active I/O”. Why ESXi hosts in this cluster do not have optimized paths to storage? I would appreciate your comment and advice.