Chapter 7. Highly Available controller pairs 877.4 Managing an HA pair configurationThis section describes the considerations and activities related to managing an HA pairconfiguration.There are the following ways to manage resources and to perform takeover/giveback fromone node to another node: Data ONTAP command-line interface (CLI) Data ONTAP FilerView IBM System Manager for N series Operations ManagerFC-AL card Yes No If an FC-AL card for the primary loop fails, the partner nodeattempts a failover at the time of failure.If the FC-AL card for the secondary loop fails, the failovercapability is disabled. However, both storage systemscontinue to serve data to their respective applications andusers, with no effect or delay.Disk drive No No If a disk fails, the storage system can reconstruct data fromthe RAID 4 or RAID DP. No failover is needed in this situation.Disk shelf (includingbackplane)No No A disk shelf is a passive backplane with dual power supplies,dual fans, dual ESH2s, and dual FC-AL loops. It is the mostreliable component in a storage system.Power supply No No Both the storage system and the disk shelf have dual powersupplies. If one power supply fails, the second power supplyautomatically kicks in. No failover is needed in this situation.Fan (storage systemor disk shelf)No No Both the storage system head and disk shelf have multiplefans. If one fan fails, the second fan automatically providescooling. No failover is needed in this situation.Cluster adapter N/A No If a cluster adapter fails, the failover capability is disabled butboth storage systems continue to serve data to theirrespective applications and users.HA pair configurationinterconnect cableN/A No The cluster adapter supports dual cluster interconnectcables. If one cable fails, the HA pair traffic (heartbeat andNVRAM data) is automatically sent over the second cablewith no delay or interruption.If both cables fail, the failover capability is disabled, but bothstorage systems continue to serve data to their respectiveapplications and users.HardwarecomponentSPOF SPOF eliminatedNon-HApairHA pair
