How to set a port mask using the CLI and GUI The command to apply a local FC port mask on CLI is  chsystem -localfcportmask mask . The  command to apply a remote FC port mask is  chsystem -partnerfcportmask mask . If you are using the GUI, click  Settings  Network Fibre Channel Ports . Then you can  select the use of a port from these options: Figure 6-5 shows the port mask in the GUI. Figure 6-5 Fibre Channel Ports menu An  I/O group  consists of two IBM SVC nodes or two IBM V7000 node canisters that share  management of volumes within a cluster. Use a single I/O group (iogrp) for all volumes that  are allocated to a particular host. This guideline has the following benefits: The number of host ports and host objects that are allowed per I/O group depends on the  switch fabric type. For more information about the maximum configurations, see  V8.2.1  Configuration Limits and Restrictions : SVC 8.2.1 Configuration Limits and Restrictions V7000 8.2.1 Configuration Limits and Restrictions Chapter 6. Hosts  285 GLYPH<SM590000> Minimizes port fan-outs within the SAN fabric GLYPH<SM590000> Maximizes the potential host attachments to IBM Spectrum Virtualize because maximums  are based on I/O groups GLYPH<SM590000> Fewer target ports to manage within the host 6.1.6 Host to I/O group mapping GLYPH<SM590000> Setting  none  means no node-to-node and no replication traffic is allowed. Only host and  storage traffic is allowed. GLYPH<SM590000> Setting  local  means only node-to-node traffic is allowed.  GLYPH<SM590000> Setting  remote  means that only replication traffic is allowed.