Administrator Guide

Synchronous replication features
19 Dell EMC SC Series: Synchronous Replication and Live Volume | CML1064
replica. When using high consistency synchronous replication, data between source and destination must be
consistent for DSM to advise it is safe to use the destination replica for recovery.
When using high availability synchronous replication (or high consistency with the ability to pause replication),
the data between source and destination volumes may or may not be consistent depending on whether the
replication was in sync or out of date at the time of the failure. If at the time of failure replication was in sync,
DSM will advise that the destination replica volume is data consistent and safe to use for recovery.
Conversely, if the synchronous replication was out of date, this means journaled transactions at the source
volume likely have not been replicated to the destination and the destination replica is not data consistent and
not recommend for use. At this point, the data recovery options would be to use a data consistent snapshot
as the recovery point or continue with using the inconsistent replica. In either case, the most recent
transactions will have been lost at the destination but recovering from a snapshot will provide a precise point
in time as the recovery point.
3.7 Dell Storage Manager DR recovery
Synchronous replication volumes are supported in the scope of the DSM predefined disaster recovery and
DR activation features. Those that have used this feature with asynchronously replicated volumes in the past
can extend the same disaster recovery test and execution processes to synchronously replicated volumes.
DSM and its core functionality is freely available to SC Series customers, making it an attractive and
affordable tool for improving recovery time objectives. Note that DR settings cannot be predefined for Live
Volumes, nor can Live Volume restore points be test activated.
3.8 Support for VMware vSphere Site Recovery Manager
Standard asynchronous or synchronous (either mode) replication types can be leveraged by VMware
®
vSphere
®
Site Recovery Manager (SRM) protection groups, recovery plans, and reprotection.
SRM version 6.1 support for stretched storage with Live Volume was added in DSM 2016 R1. Supported
deployment configurations are outlined in the document, Dell EMC SC Series Best Practices with VMware
Site Recovery Manager. For more information on use cases and integrating stretched storage with SRM,
please see the Site Recovery Manager Administration documentation provided by VMware.