https://www.ibm.com/docs/en/sanvolumecontroller/8.5.0?topic=rnn-replacing-nodes-nondisruptively-san-volume-controller-2145-sv3-node

IBM SAN Volume Controller 2145-SV3 node have some restrictions compared to legacy IBM SAN Volume Controller nodes.

  They cannot do real-time compression.
  They cannot be connected to SAS expansion enclosures.
  They cannot service iSCSI I/O on the built-in Ethernet management ports.
  They do not support iSER host I/O.
  They do not support RoCE for clustering or HyperSwap.

If one of the nodes that you want to replace is the system configuration node (config_node:yes), replace it last.

svcinfo lsnode -delim :
lsnodevpd node_name_or_node_ID
lsdependentvdisks -node node_name_or_node_id
sainfo lsservicestatus

satask installsoftware -file IBM_5.0.12 -ignore

sainfo lsservicenode

satask chvpd -wwnn 500507680F00FFFF -fcportmap 11-11,12-12,13-13,14-14,21-21,22-22,23-23,24-24