5.5

Table Of Contents
10 Review the settings and click Finish to establish replication.
vSphere Replication starts an initial full synchronization of the virtual machine files to the designated
datastore on the target site.
Configure Replication for Multiple Virtual Machines
You can configure replication for multiple virtual machines using the multi-VM configure replication wizard.
When you configure replication, you set a recovery point objective (RPO) to determine the period of time
between replications. For example, an RPO of 1 hour seeks to ensure that a virtual machine loses no
more than 1 hour of data during the recovery. For smaller RPOs, less data is lost in a recovery, but more
network bandwidth is consumed keeping the replica up to date.
Every time that a virtual machine reaches its RPO target, vSphere Replication records approximately
3800 bytes of data in the vCenter Server events database. If you set a low RPO period, this can quickly
create a large volume of data in the database. To avoid creating large volumes of data in the
vCenter Server events database, limit the number of days that vCenter Server retains event data. See
Configure Database Retention Policy in the vCenter Server and Host Management Guide. Alternatively,
set a higher RPO value.
vSphere Replication guarantees crash consistency amongst all the disks that belong to a virtual machine.
If you use VSS quiescing, you might obtain a higher level of consistency. The available quiescing types
are determined by the virtual machine's operating system. See Compatibility Matrixes for vSphere
Replication 5.5 for Microsoft Volume Shadow Copy Service (VSS) quiescing support for Windows virtual
machines.
You can configure virtual machines to replicate to a Virtual SAN datastore on the target site. See Using
vSphere Replication with Virtual SAN Storage for the limitations when using vSphere Replication with
Virtual SAN.
Note VMware Virtual SAN is a fully supported feature of vSphere 5.5u1.
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You can use Virtual SAN in production environments with vSphere Replication 5.5.1 and vSphere
5.5u1.
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Virtual SAN is an experimental feature in vSphere 5.5. You can perform testing with Virtual SAN with
vSphere Replication 5.5.0 and vSphere 5.5, but it is not supported for use in production
environments. See the release notes for the vSphere Replication 5.5.0 release for information about
how to enable Virtual SAN in vSphere 5.5.
Configuring vSphere Replication on a large number of virtual machines simultaneously when using Virtual
SAN storage can cause the initial full synchronization of the virtual machine files to run very slowly. Initial
full synchronization operations generate heavy I/O traffic and configuring too many replications at the
same time can overload the Virtual SAN storage. Configure vSphere Replication on batches of a
maximum of 30 virtual machines at a time.
VMware vSphere Replication Administration
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