Administrator Guide

level of fault-tolerance, which improves the reliability of maintaining saved data, and permits accessibility to the same
stored data. 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 destination (also
known as a target) that acts as a replica of the original source data.
ANMERKUNG: Starting with Release 2.0, 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 (DR Series
systems running Release 2.0.x software can only replicate with other DR Series systems that run the same release
system software). For example, Release 2.0.x systems will not be able to replicate with Release 2.1 or Release 3.0
systems, but can replicate with systems running Release 2.0.0.1 or 2.0.0.2.
ANMERKUNG: It is important to distinguish the difference between data that has been processed by backup and
data that has been processed by replication, since backup saves a copy of data that remains unchanged for a long
period of time.
Targets with replica data 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 the storage replication where the backed up
and deduplicated data is replicated in real-time or via a scheduled window. In a replication relationship between two DR
Series systems, this means that a relationship exists between a pair of systems, one acting as the source and the other
as a target in the replication pair (for example, with acme-west and acme-east). When this type of replication
relationship exists between distinct containers on two distinct DR Series systems, it can be considered bidirectional in
the sense that:
• West1 container on the acme-west source system can replicate data to a separate East1 container on the
acme-east target system.
• The East2 container on the target acme-east system can also replicate data back to the West2 container on the
source acme-west system.
This form of replication involves separate containers on two distinct DR Series systems. Target containers in replication
must always act as read-only, while source containers can act as read-write. Unlike NFS and CIFS containers, OST and
RDS container replication is handled by the two supported Data Management Applications (DMAs) on media servers.
For more information on OST, see Understanding OST. For more information on RDS, see Configuring and Using Rapid
Data Storage.
ANMERKUNG: OST and RDS containers are categorized as Rapid Data Access (RDA) containers in DR Series
systems.
This release of the DR Series system supports the 32:1 replication of data, whereby up to 32 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.
ANMERKUNG: Be aware that 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 in a replication pair reside in different Active Directory (AD) domains, then the data that
resides on the target DR Series system may not be accessible. When AD is used for authentication for DR Series
systems, the AD information is saved with the file. This can serve to restrict user access to the data based on the type of
AD permissions that are in place.
ANMERKUNG: 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.
Reverse Replication: The concept of reverse replication is not supported on DR Series systems. This is because replica
containers are always in a R-O (read-only) mode on the DR Series system, thus making write operations a non-
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