5.5

Table Of Contents
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Stop Replicating a Virtual Machine
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Reconfiguring Replications
How the Recovery Point Objective Aects Replication
Scheduling
The Recovery Point Objective (RPO) value you set during replication configuration affects replication
scheduling.
If you set an RPO of x minutes, the latest available replication instance can never reflect a state that is
older than x minutes. A replication instance reflects the state of a virtual machine at the time the
replication starts.
You set the RPO during replication configuration to 15 minutes. If the replication starts at 12:00 and it
takes five minutes to transfer to the target site, the instance becomes available on the target site at 12:05,
but it reflects the state of the virtual machine at 12:00. The next replication can start no later than 12:10.
This replication instance is then available at 12:15 when the first replication instance that started at 12:00
expires.
If you set the RPO to 15 minutes and the replication takes 7.5 minutes to transfer an instance,
vSphere Replication transfers an instance all the time. If the replication takes more than 7.5 minutes, the
replication encounters periodic RPO violations. For example, if the replication starts at 12:00 and takes 10
minutes to transfer an instance, the replication finishes at 12:10. You can start another replication
immediately, but it finishes at 12:20. During the time interval 12:15-12:20, an RPO violation occurs
because the latest available instance started at 12:00 and is too old.
The replication scheduler tries to satisfy these constraints by overlapping replications to optimize
bandwidth use and might start replications for some virtual machines earlier than expected.
To determine the replication transfer time, the replication scheduler uses the duration of the last few
instances to estimate the next one.
Replicating a Virtual Machine and Enabling Multiple Point
in Time Instances
You can recover virtual machines at specific points in time (PIT) such as the last known consistent state.
When you configure replication of a virtual machine, you can enable multiple point in time (PIT) instances
in the recovery settings in the Configure Replication wizard. vSphere Replication retains a number of
snapshot instances of the virtual machine on the target site based on the retention policy that you specify.
vSphere Replication supports maximum of 24 snapshot instances. After you recover a virtual machine,
you can revert it to a specific snapshot.
During replication, vSphere Replication replicates all aspects of the virtual machine to the target site,
including any potential viruses and corrupted applications. If a virtual machine suffers from a virus or
corruption and you have configured vSphere Replication to keep PIT snapshots, you can recover the
virtual machine and then revert it to a snapshot of the virtual machine in its uncorrupted state.
VMware vSphere Replication Administration
VMware, Inc. 57