Release Notes

SC Series features
14 Dell EMC SC Series: Performance and Availability | 4024-BP-SC
3 SC Series features
This section describes the different SC Series features and how they can be configured to optimize SC Series
storage performance.
3.1 Data Progression
Data Progression is the data movement engine in the SC Series array that converts data to a more efficient
RAID type when a snapshot is taken. It also moves data to an appropriate tier of storage based upon the
data’s access frequency in conjunction with the storage profile of the volume.
3.2 Replication
SC Series arrays support two types of replication: synchronous and asynchronous.
Asynchronous replication: The system acknowledges a server write I/O as soon as the source system can
guarantee the write will be committed to disk. Then, the write is replicated to the target system at a later point
in time.
Synchronous replication: The server write I/O is not acknowledged until both the source and target systems
can guarantee the write will be committed to disk. There are two synchronous replication modes available:
• High Availability Mode: This accepts I/O requests to the primary volume when the secondary volume
is unavailable (or when latency is too high) to avoid interrupting service. However, if writes are
accepted to the primary volume, the secondary volume data becomes stale.
• High Consistency Mode: This prevents I/O requests to the primary volume when the secondary
volume is unavailable to make sure that the volumes remain identical. The primary volume cannot be
modified during this time, which can interrupt operations.
The SCv20x0 platform only supports asynchronous replication.
3.2.1 Replication topology
Mixed topology allows the source volume to be replicated to two destination volumes where one is
synchronous and the additional replications are asynchronous (1 to N asynchronous destinations where N is
defined by SCOS, currently 2).
Cascade topology allows asynchronous replications to be chained to synchronous or asynchronous
replication destination volumes.
Hybrid topology is created by combining mixed and cascade topology types.
3.3 Live Migrate and Live Volume
Live Migrate and Live Volume expand on the replication capabilities of the SC series system.
Live Migrate is included with the purchase of an SC Series array and allows for volume movement with no
down time to another SC Series array. No additional license is needed for Live Migrate, which is available
with SCOS 7.1 or higher.
Live Migrate leverages replication. It maps the volume to both instances of the volume, although the server
sees both volumes as one volume, but with multiple paths, and will send reads and writes down any path. In