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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
When you set a Recovery Point Objective (RPO) value during replication configuration, you determine the
maximum data loss that you can tolerate. The RPO value affects replication scheduling, but
vSphere Replication does not adhere to a strict replication schedule.
For example, when you set the RPO to 15 minutes, you instruct vSphere Replication that you can tolerate
losing the data for up to 15 minutes. This does not mean that data is replicated every 15 minutes.
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.
Assume that during replication configuration you set the RPO 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.
VMware vSphere Replication Administration
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