Administrator Guide

VMware vSphere and Live Volume
58 Dell EMC SC Series: Synchronous Replication and Live Volume | CML1064
8.10 Tiebreaker service
A tiebreaker service is built into the Dell Storage Manager Data Collector as well as the Remote Data
Collector, and acts as a quorum to facilitate Live Volume automatic failover. It also plays an important role in
preventing split-brain conditions should a network or fabric partition between arrays occur. The tiebreaker
should be located at a site physically independent of arrays participating in a Metro Cluster. This may be in a
customer-owned data center or public cloud. Although tiebreaker availability is not required for Live Volume
I/O during healthy operating conditions, the tiebreaker service is required to act on unplanned Live Volume
component outages (typically, the result is automatic failover but this is not always the case) and network
latency to the tiebreaker from each array must not exceed 200 ms RTT.
8.11 Common automatic failover scenarios
The following sections outline failure scenarios and the resulting Live Volume automatic failover behavior.
These are scenarios commonly asked about by customers, not necessarily scenarios that are likely to
commonly occur.
8.11.1 Primary Live Volume array failure
If an unplanned event impacts an SC Series array that is hosting a primary Live Volume, Live Volume
availability is automatically failed over to the surviving array.
Primary Live Volume failure