Using HA Manager Modes

The snhamgr rules for mode pairings are easier to understand by following a BAAB strategy for transitioning into and out of config or single mode. In this strategy, B stands for the redundant node, and A stands for the node to be placed into config or single mode. Enter the desired cluster state by transitioning B's mode first, then A's. Reverse this when exiting the cluster state by transitioning A's mode, then B's.

For the configuration-session example, place B in locked mode, then place A in config mode to start a configuration session. At the end of the session, place A in default mode, then place B in default mode.

For the single-server cluster example, shut down Linux and power off B, then designate it peerdown with the 'snhamgr peerdown' command on A, then place A in single mode. At the end of the session, place A in default mode, then designate B as up with the 'snhamgr peerup' command on A, then power on B.