Draft Document for Review December 5, 2019 4:33 pm 8456ch_DS_HMC_Plan.fm The HMC connects to the customer network, and provides access to functions that can be  used to manage the DS8900F. Management functions include logical configuration, problem  notification, call home for service, remote service, and Copy Services management.  These Management functions can be performed from the DS8000 Storage Management GUI  (DS GUI), DS command-line interface (DS CLI), or other storage management software that  supports the DS8900F. For example, clients who use an external Copy Services Manager (CSM) for advanced  functions, such as Metro Mirror or FlashCopy are communicating to the storage system by  connecting the CSM server to the HMCs as management entry point. The HMC provides connectivity between the DS8000 and Encryption Key Manager servers  (SKLM), if used and also provides the functions for remote call-home and remote support  connectivity. The HMCs are equipped with Ethernet connections for the client’s network. For more  information, see 8.1.3 Private and Management Ethernet networks on page 207. To provide continuous availability of access to the management console functions, the  DS8900F includes a second management console as default. One HMC takes over the  primary and the other MC the secondary role. The role is not determined by the physical  position of the HMC and can be chosen at installation time or later on by a customer service  representative. using the service management console. However, it is very common that the  HMC on the left (when facing the rack) is designated as the primary. To set an HMC role, from the Service Console shown in Figure 8-3, select  HMC  Management  Query/Activate HMC Role Section The secondary HMC is now default and it is needed for redundancy reason as example for  encryption management or Advanced Copy Services functions. For more information about  the secondary HMC, see 8.6 Secondary Management Console on page 229. The HMCs communicate with the storage facility internally through a pair of redundant  Ethernet networks, which are designated as the Black Network and the Gray Network. There  are two switches which are isolated from each other and they are located in the management  enclosure (ME). Figure 8-3 Query and Change HMC Role 8.1.3 Private and Management Ethernet networks Chapter 8. IBM DS8900F Management Console planning and setup  207