558 Implementing the IBM Storwize V7000 with IBM Spectrum Virtualize V8.2.1
As shown in Figure 11-99 on page 557, there are two systems: 
– System A
– System B
A single remote copy port group 1 is configured on two Ethernet ports, one each on Node 
A1 and Node A2 on System A. Similarly, a single remote copy port group is configured on 
two Ethernet ports on Node B1 and Node B2 on System B. 
Although two ports on each system are configured for remote copy port group 1, only one 
Ethernet port in each system actively participates in the IP partnership process. This 
selection is determined by a path configuration algorithm that is designed to choose data 
paths between the two systems to optimize performance. 
The other port on the partner node in the I/O Group behaves as a standby port that is 
used if there is a node failure. If Node A1 fails in System A, IP partnership continues 
servicing replication I/O from Ethernet Port 2 because a failover port is configured on 
Node A2 on Ethernet Port 2. 
However, it might take some time for discovery and path configuration logic to reestablish 
paths post failover. This delay can cause partnerships to change to Not_Present for that 
time. The details of the particular IP port that is actively participating in IP partnership is 
provided in the lsportip output (reported as used). 
This configuration has the following characteristics:
– Each node in the I/O group has the same remote copy port group that is configured. 
However, only one port in that remote copy port group is active at any time at each 
system. 
– If the Node A1 in System A or the Node B2 in System B fails in the respective systems, 
IP partnerships rediscovery is triggered and continues servicing the I/O from the 
failover port.
– The discovery mechanism that is triggered because of failover might introduce a delay 
where the partnerships momentarily change to the Not_Present state and recover.
/SM590000Two 4-node systems in IP partnership over a single inter-site link (with failover ports 
configured), as shown in Figure 11-100 on page 559 (configuration 3).