Which condition trigger SM-BC failover without node fail

[AllenChang]

if the node pair of source cluster not fail,

which condition make SnapMirror Business Continuity trigger failover ?

[Ontapforrum]

As per SMBC TR, it is designed for Business Continuity with zero RPO & RTO, and it's triggered (automatic unplanned failover) for complete SITE Failure (Source Cluster down). For this to happen, each source & dest cluster must be configured with 'ONTAP MEDIATOR'.

Without Nodes failure, you are probably looking at Planned failover : Which is initiated by the administrator of the secondary cluster. The operation requires switching the primary and secondary roles so that the secondary cluster takes over from the primary. The new primary cluster can then begin processing input and output requests locally without disrupting client operations.

TR has all the info:
https://www.netapp.com/pdf.html?item=/media/21888-tr-4878.pd

This article is very good:
https://kb.vmware.com/s/article/83370#

[AllenChang]

I mean  if any component fail will trigger automatic failover?
I try to disalbe svm's lif and the Inter Cluster LIF then the cluster failover,

If any other component failure will trigger the failover?

[jaikumar]

SM-BC will failover in following conditions
* Planned Failover (where the user does a snapmirror failover)

*Automated Unplanned Failover
Note: For both events to happen , Mediator must be configured.
---
What will cause Automated Unplanned failover ?
#1 Both the Nodes in the Primary Cluster Goes does 
#2 Primary Cluster becomes isolated , which means that Primary Cluster Nodes are Up both its connectivity to the Secondary Cluster as well as the Mediator is Lost.
There are certain nuances for #2 like
* Connectivity to the Mediator and Secondary Cluster must be lost almost simultaneous , for example , if the connectivity to the Secondary Cluster is lost first then the relationship goes Out of Sync (no longer a in ZRPO state) and hence the Failover will NOT happen. 

[BRadyovich]

It's usually when something funky happens on the source cluster, not necessarily a node going kaput. Think network glitches, config issues, or storage problems.

[chenguanghui]

hello:

When the primary cluster is shut down or isolated, the source data is damaged or lost, the disk is damaged, and the network is interrupted or the latency is particularly high. Sudden power outages, these trigger failovers

i hope to help you