To configure batches of virtual machines for replication from one vCenter Server instance to another, you can select multiple virtual machines and start the 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 the data for no more than 1 hour during the recovery. For smaller RPO values, 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 5.8 for Microsoft Volume Shadow Copy Service (VSS) quiescing support for Windows virtual machines.

You can use vSphere Replication with a Virtual SAN datastore on the source and target sites. 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 and later.

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.

Prerequisites

To replicate virtual machines using vSphere Replication, you must deploy the vSphere Replication appliance at the source and target sites. You must power on the virtual machines to begin replication.

Procedure

  1. On the vSphere Web Client Home page, click vSphere Replication.
  2. Select a vCenter Server and in the left pane, double click Virtual Machines.
    In the Related Objects tab, the Virtual Machines tab lists the virtual machines.
  3. Select the virtual machines to replicate using the Ctrl or Shift keys.
  4. Right-click the virtual machines and select All vSphere Replication Actions > Configure replication.
    The virtual machines pass a validation check before they can be configured for replication.
  5. Click Next.
  6. Select Replicate to a vCenter Server.
    To configure replication to a cloud provider, see vSphere Replication for Disaster Recovery to the Cloud.
  7. Select the target site.
    • If you have already connected the source and target sites, select the target site from the list.
    • If you have not connected the source and target sites, and the target site is local, select the target site from the list.
    • If you have not connected the source and target sites, and the target site is remote, click Add Remote Site and enter the IP or name, and credentials to connect to the site.
  8. Accept the automatic assignment of a vSphere Replication server or select a particular server on the target site.
  9. Select the target location datastore. Optionally, you can select the virtual machine storage policy.
  10. (Optional) On the Replication options page, select the quiescing method for the guest operating system of the source virtual machine.
    Note: Quiescing options are available only for virtual machines that support quiescing.
  11. On the Recovery settings page, use the RPO slider or the time spinners to set the acceptable period for which data can be lost in the case of a site failure.
    The available RPO range is from 15 minutes to 24 hours.
  12. (Optional) To save multiple replication instances that can be converted to snapshots of the source virtual machine during recovery, select Enable in the Point in time instances pane, and adjust the number of instances to keep.
    Note: You can keep up to 24 instances per virtual machine. This means that if you set vSphere Replication to keep 6 replication instances per day, the maximum number of days you can set is 4 days.

    The number of replication instances that vSphere Replication keeps depends on the configured retention policy, but also requires that the RPO period is short enough for these instances to be created. For example, if you set vSphere Replication to keep 6 replication instances per day, the RPO period should not exceed 4 hours, so that vSphere Replication can create 6 instances in 24 hours.

  13. Click Next.
  14. Choose whether to use replication seeds.
    This option searches the selected target datastore for disk files that can be used as replication seeds. If candidate files are found on the target datastore, confirm whether to use those files as seeds.
  15. On the Ready to complete page, review the replication settings, and click Finish.

Results

vSphere Replication starts an initial full synchronization of the virtual machine files to the designated datastore on the target site.