The DR Series system uses an active form of replication that lets you configure a primary-backup scheme. During
replication, the system processes data storage requests from a specified source to a specified replica target, which
acts as a replica of the original source data. This replica can then be cascaded optionally to a third location called a
Cascaded replica for an additional copy.
NOTE: The DR Series system software includes version checking that limits replication only between other DR
Series systems that run the same system software release version. If versions are incompatible, the administrator
is notified by an event.
NOTE: Replication for VTL containers is not currently supported. However this feature is actively being worked on
and will be made available in a future DR Series system release.
Replicas/Cascaded replicas are read-only and are updated with new or unique data during scheduled or manual
replications. The DR Series system can be considered to act as a form of a storage replication process in which the
backup and deduplication data is replicated in real-time or via a scheduled window in a network environment. In a
replication relationship between two or three DR Series systems, this means that a relationship exists between a
number of systems. One system acts as the source and the other as a replica, with an optional third cascaded replica if
you have chosen to keep two instances of replicated data in your backup workflow.
Replication is done at the container level and is one directional from source to replica to optional cascaded replica;
however, since replication is done at the container level you can set up various containers to meet your specific
replication requirements for your specific workflow. This form of replication is supported for the CIFS, NFS, Rapid CIFS,
and Rapid NFS protocols and is fully handled by the DR Series system.
NOTE:
Refer to the
Dell DR Series Interoperability Guide
for information about the maximum number of files replicated per
container at a time per DR Series system.
Unlike NFS, CIFS, Rapid NFS or Rapid CIFS containers, RDA with OST, RDA with NetVault Backup, and RDA with vRanger
container replication is handled by Data Management Applications (DMAs) media servers.
The DR Series system supports the 64:1 replication of data (32:1 if on DR4X00 and 8:1 on DR2000v), whereby up to 64
source DR Series systems can write data to different individual containers on a single, target DR Series system. This
supports the use case where branch or regional offices can each write their own data to a separate, distinct container
on a main corporate DR Series system.
NOTE: The storage capacity of the target DR Series system is directly affected by the number of source systems
writing to its containers, and by the amount being written by each of the source systems.
If the source and target systems (replica or cascaded replica) are in different Active Directory (AD) domains, then the
data that resides on the target system may not be accessible. When AD is used to perform authentication for DR Series
systems, the AD information is saved with the file. This can act to restrict user access to the data based on the type of
AD permissions that are in place.
NOTE: This same authentication information is replicated to the target DR Series system when you have
replication configured. To prevent domain access issues, ensure that both the target and source systems reside in
the same Active Directory domain.
Replication Seeding
The DR Series systems support replication seeding, which provides the ability to create a local seed and place it in a
remote system. The seed backup is a process on the source DR Series system, which collects all of the unique data
chunks from the containers and stores them on the target device. This is helpful if you have a new replication target DR
to set up, the amount of data to be replicated is very large, and the network bandwidth is low. You can seed the target
replica with the source data saved on a third party device, for example, a CIFS—mounted share, attach it to the target
DR and then get the data into the target DR. Once the seeding is complete, replication is enabled between source and
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