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7 Using Dell PS Series Asynchronous Replication | TR1052
2 Replication planning
Below are some guidelines for getting started with replication planning.
1. Plan the replication configuration for your groups and volumes. For each volume, determine the
replication space requirements (section 2.2) for the primary and secondary groups. This will help in
determining the local space required for replication and choosing the best replication partner for
each volume.
2. Configure one or more replication partners (section 3). For each partner configured, an
administrator must log into the partner and configure the primary group as a replication partner,
making sure to delegate sufficient space (section 2.2) to the primary group.
3. Configure each volume for replication (section 3.1). Specify the replication partner, local
replication reserve, replica reserve on the partner, and whether to maintain the failback snapshot.
4. Create a replica on demand (section 4), or set up a schedule (section 2.6) to create replicas
automatically at a specified time and frequency. Using a schedule, you can specify how many
replicas to keep.
5. Regularly monitor (section 5.1.1) to ensure the replicas have completed and that the correct
number of replicas is stored on the partner.
6. Adjust values over time as needed. For example:
- Adjust the schedule (section 3.1.1) to create more replicas, retain fewer, or to create them at a
different interval or time.
- Increase or decrease the amount of delegated space (section 2.2) on the partner, depending
on your actual space usage and needs.
- Increase or decrease replicated volume’s replica reserve (section 2.2).
Answering the following questions will help determine which groups to configure as replication partners,
how often to replicate the volumes, how many replicas to keep, how to coordinate the replication plan,
and whether or not to enable failback on the volumes:
 How large are the volumes?
 How much and how often does volume data change?
 How many copies of the volume (replicas) should be kept?
 How much space is available on each group to store a partner’s replicas?
 What are the business recovery needs for the applications using the volumes?
- Recovery Time Objective (RTO): The amount of time within which a business process must be
restored after a disaster or disruption. The RTO determines whether or not to keep a failback
snapshot. See the section, Failover and failback considerations.
- Recovery Point Objective (RPO): The acceptable amount of data loss for a specific amount of
time. The RPO determines the necessary frequency of replication.
 Who manages the replication and data recovery process?