Administrator Guide

Introduction to synchronous replication
7 Dell EMC SC Series: Synchronous Replication and Live Volume | CML1064
1 Introduction to synchronous replication
While SC Series storage supports both asynchronous and synchronous replication, this document focuses
primarily on synchronous replication.
By definition, synchronous replication ensures data is written and committed to both the replication source
and destination volumes in real time. The data is essentially written to both locations simultaneously. In the
event that the data cannot be written to either of the locations, the write I/O will not be committed to either
location, ensuring transactional consistency, and a write I/O failure will be issued to the storage host and
application where the write request originated. The benefit synchronous replication provides is guaranteed
consistency between replication sites resulting in zero data loss in a recovery scenario.
Dell Technologies advises customers to understand the types of replication available, their applications, and
their business processes before designing and implementing a data protection and availability strategy.
1.1 Features of SC Series synchronous replication
Mode migration: Existing replications may be migrated to an alternate type without rebuilding the replication
or reseeding data.
Live Volume support: Live Volumes may leverage any available type of replication offered with SC Series
storage including both modes of synchronous (high consistency or high availability) and asynchronous.
Live Volume managed replication: Live Volume allows an additional synchronous or asynchronous
replication to a third SC Series array that can be DR activated using Dell™ Storage Manager (DSM).
Preserve Live Volume (manual failover): In the event an unplanned outage occurs impacting availability of
a primary Live Volume, the secondary Live Volume can be promoted to the primary Live Volume role
manually using DSM.
Live Volume automatic failover: In the event an unplanned outage occurs impacting availability of a primary
Live Volume, the secondary Live Volume can be promoted to the primary Live Volume role automatically.
Live Volume automatic restore: After Live Volume automatic failover has occurred, Live Volume pairs may
be automatically repaired after the impacted site becomes available.
1.2 Synchronous replication requirements
Replicating volumes between SC Series systems requires a combination of software, licensing, storage, and
fabric infrastructure. The following sections itemize each requirement.
1.2.1 Dell Storage Manager
Dell™ Storage Manager (DSM) 2018 or newer is required to leverage all available replication and Live
Volume features.
1.2.2 Storage Center OS
Dell Storage Center OS (SCOS) 7.3 or newer is required to leverage all available replication and Live Volume
features.