Any controller unit will boot from the master controller unit’s drives. All configuration data, including syslog information, is located on the master controller unit’s drives.
How Partner Groups Work
If the master controller unit fails and the “heartbeat” between it and the alternate master stops, this failure causes a controller failover, where the alternate master assumes the role of the master controller unit. The new master (formerly the alternate master) takes the IP address and the MAC address from the old master and begins to function as the administrator of the storage system. It will also be able to access the former master controller unit’s drives. The former master controller unit’s drives will still be used to store syslog information, system configuration information, and bootcode. Should it become necessary to reboot the storage system while the master controller unit is inactive, the alternate master will use the former master controller unit’s drives to boot.
Note – After the failed master controller is back online, it remains the alternate master controller and, as a result, the original configuration has been modified from its original state.
In a redundant partner group configuration, the units can be set to do a path failover operation. Normally the volumes or LUNs that are controlled by one unit are not accessible to the controller of the other. The units can be set so that if a failure in one controller occurs, the remaining one will accept I/O for the devices that were running on the failed controller. To enable this controller failover operation, multipathing software, such as VERITAS Volume Manager, Sun StorEdge Traffic Manager software, or Solaris Alternate Pathing (AP) software must be installed on the data application host.
Note – In order for a feature such VERITAS DMP to access a LUN through both controllers in a redundant partner group, the mp_support parameter must be set to rw to enable this feature. If you are using Sun StorEdge Traffic Manager, the mp_support parameter must be set to mpxio. For information on setting the mp_support parameter and options, refer to the Sun StorEdge T3 and T3+ Array Administrator’s Guide.
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