Administrator Guide

Synchronous replication features
18 Dell EMC SC Series: Synchronous Replication and Live Volume | CML1064
newer, Live Volume is designed to work in conjunction with asynchronous and synchronous replication types.
In addition, Live Volume supports many of the current synchronous replication features such as modes of
operation and mode migration.
3.5.1 Preserve Live Volume
In SCOS 6.5 or newer, recovering data from a secondary Live Volume, when the primary Live Volume is
unavailable, is faster, easier, and more flexible. Secondary Live Volumes may be promoted to the primary
Live Volume role that preserves volume identity and storage host mappings. Alternatively, data on a
secondary Live Volume may be recovered by creating a new a View Volume and then mapping that View
Volume to one or more storage hosts.
3.5.2 Live Volume automatic failover
SCOS 6.7 introduced automatic failover for Live Volumes. Depending on the nature of the unplanned outage,
the recovery process is similar to the Preserve Live Volume feature except that it is completely automated
and occurs within a matter of seconds, and at scale.
3.5.3 Live Volume automatic restore
When an unplanned outage occurs, Live Volume automatic failover provides high availability for configured
volumes. However, at this point, volume availability is at risk should a second unplanned event impact the
remaining system. If the original outage is minimal in scope and the site can be brought back online, the Live
Volume automatic restore feature repairs the Live Volume back to a redundant state with no administrator
intervention required. Note that a Live Volume role swap does not occur as part of this process meaning a
Secondary Live Volume which was recovered as a Primary Live Volume during automatic failover will remain
a Primary Live Volume after the automatic restore.
3.5.4 Live Volume managed replication
A Live Volume managed replication is an additional replication and replica volume that uses the primary Live
Volume as its replication source. The Live Volume managed replication may be synchronous or
asynchronous depending on the Live Volume configuration. To maintain data integrity and consistency, when
a Live Volume swap role or failover occurs, the Live Volume managed replication persistently follows the
primary Live Volume as its source of replication.
Live Volume managed replication before and after swap role or failover
3.6 Dell Storage Manager recommendations
Dell Storage Manager periodically checks the status of replication and records the progress of completeness.
In the event of a failure at the source site, DSM provides a safe recommendation on the use of the destination