Administrator Guide

VMware vSphere and Live Volume
69 Dell EMC SC Series: Synchronous Replication and Live Volume | CML1064
One differentiator between standard replication and Live Volume managed replication is that the source
volume of a managed replication is dynamic and changes as Live Volume role swaps occur. The easiest way
to think of this is to understand that the managed replication source is always the primary Live Volume.
Because the primary Live Volume role can shift manually or automatically between arrays, the flow of
replicated data will also seamlessly and automatically follow this pattern. The reason for this is that the
primary Live Volume is the volume where write I/O is first committed. Therefore, and especially in an
asynchronous Live Volume configuration, in the event of an unplanned outage or disaster that disables both
Live Volumes, data should be recovered from the most transaction consistent volume to minimize loss of
data. For synchronous Live Volumes, transaction inconsistency is less of an issue because both primary and
secondary Live Volumes should have a sync status of current and not out of date unless the synchronous
replication was paused or became out of date due to excess latency in high availability mode. Disaster
recovery at a remote site is a good use case for the Live Volume managed replication feature. However, Live
Volume managed replications are not explicitly supported with vSphere Site Recovery Manager. LUN
presentation and data recovery on a managed replication can be handled automatically by DSM, but before
virtual machines can be powered on, they must be registered into vSphere inventory, which may require a
manual DR-documentation or scripted process.
Non-uniform Live Volume pair with managed replication at a third site