## PowerHA SystemMirror fallover issues 

This topic describes the potential fallover issues. 

## PowerHA SystemMirror fallover is not triggered after a node crash or reboot 

Check whether either more than half of the nodes in the cluster are online or exactly half of the nodes are online and the tiebreaker is reserved. If less than half of the nodes are online, start additional nodes. If exactly half of the nodes are online, check the attribute of the active tiebreaker. 

The possible causes are as follows: 

GLYPH<SM590000> Either more than half of the nodes in the cluster are online, or exactly half of the nodes are online and the tiebreaker is reserved. If less than half of the nodes are online, start additional nodes. If exactly half of the nodes are online, check the attribute of the active tiebreaker by using the clmgr query cluster command. 

GLYPH<SM590000> The split policy must be set as None and if it is set as Manual, the user intervention is required for fallover after the node restarts. 

GLYPH<SM590000> The policy of RG must be Fallback to Home Node (FBHN), which can be checked by using the clmgr query rg  command. 

