Mount Failure - Multibus Failover Mode

Problem. EVM does not correctly mount some BCV units when the storage is configured in multibus failover mode.

Cause. EVM cannot track target IDs and, in multibus failover mode, mount problems can occur when units assigned to a single host bus adapter appear as multiple target IDs.

In multibus failover mode, both pairs of controller ports are active and the default offset for each port is 0. Depending on the cabling configuration, a host bus adapter may have two entries in the HSG connection table. One entry is ONLINE to THIS controller and the other entry is ONLINE to the OTHER controller. Because each controller port has its own World Wide ID, when the two ports of a controller appear to one adapter they are interpreted by the host as two separate target IDs.

In this configuration, if the units assigned to a given adapter are mixed between the two connections, they appear to the host as two different target IDs.

Solution: Set Appropriate Access IDs. To eliminate the possibility of mount problems in multibus failover mode, you should set the appropriate Access IDs to ensure that all units assigned to a given adapter are online to the same port of the same controller.