Performing Live Sync Failover or Failback

For virtual machines created and maintained by Live Sync operations, you can execute failover scenarios from the Live Sync Monitor tab.

After a virtual machine has failed over, you can perform a failback operation to return the VM to the original site or a new primary site. A failback operation performs a backup of the VM at the failover site and uses that data to replicate the VM back to the primary site. If the virtual machine already exists at the primary site, only incremental updates are written from the failover site.

To back up destination virtual machines after a failover, see Scheduling Backups for Destination VMs after a Failover.

Note: Configuration changes made to a virtual machine at a failover site (such as adding or expanding disks or changing memory and CPU information) are not replicated back to the primary site during a failback operation.

For information about failover and failback operations, see Virtual Machine Failover Status and Failback Status Report.

The transport mode for Live Sync operations is selected automatically based on the environment, and is not configurable.

Before You Begin

To perform failover or failback operations for virtual machines, you must meet the following requirements:

  • Virtual machines included in a failover operation must have been replicated at least once, and must have a status of In Sync, Needs Sync, or Failover Failed.
  • Virtual machines included in a failback operation must have a status of Failover Complete or Failback Failed.


  1. Open the Live Sync Monitor tab from the instance, backup set, or subclient:
    • From the instance, right-click VMware and select Live Sync Monitor.
    • From the backup set, right-click the backup set and select All Tasks > Live Sync > Monitor.
    • From the subclient, right-click the subclient and select Live Sync > Monitor.
  2. On the Live Sync Monitor tab, select the rows for one or more virtual machines, right-click and point to Failover, and select one of the following options to execute a failover scenario:
    • Test Boot VM - Powers on the destination virtual machines to verify that they are ready for use in the event of a disaster. To avoid conflicts with the source VM and ensure that the virtual machine is not modified by the test boot, this scenario takes a snapshot of the virtual machine before the test boot, boots destination VMs with network connections disabled, and reverts to the snapshot afterwards.

      Note: For Test Boot VM, select virtual machines that are part of the same Live Sync schedule.

    • Planned Failover - Performs a planned failover so that you can test the failover process or perform maintenance on your primary site.

      Note: Planned failover is only supported when the Live Sync schedule is configured to use regular streaming backups. Planned failover is not supported if the schedule is configured to run from SnapProtect backup copies.

      This option triggers the following actions:

      1. Power off the source VMs.
      2. Perform an incremental backup of the source VMs to capture the latest data.
      3. Run Live Sync to apply the most recent updates for destination VMs in the disaster recovery site.
      4. Disable Live Sync.
      5. Power on the destination VMs at the disaster recovery site with appropriate network connections and IP addresses.
    • Unplanned Failover - In the event that the primary site is unavailable, this option disables Live Sync and powers up destination VMs at the disaster recovery site with appropriate network connections and IP addresses.

      Note: For an unplanned failover, some changes on the source VM might not be synced to the destination VM. For this reason, it is best to use the Failback option only after a planned failover.

  3. For virtual machines that have been failed over, you can execute a Failback operation. 
    1. On the Live Sync Monitor tab, select the rows for one or more virtual machines, right-click and point to Failback.

      You can only execute a Failback operation for virtual machines from the same schedule.

    2. In the Failback Virtual Machines dialog box, provide the information described in Failback Configuration Options.
    3. Click OK.

    After a failback operation, the next backup of the source VM will be a full backup.

    Note: If you fail back to a different site than the original VM, or if the source VM no longer exists at the primary site, make sure the new primary VM is included in a subclient for backups. Also, either edit the existing Live Sync schedule to remove and add the new primary VM, or create a new Live Sync schedule to include the VM.  The next Live Sync operation will fully replicate the source virtual machine.

  4. Click OK to execute the selected failover scenario.

Failback Configuration Options

The following options are available in the Failback Virtual Machines dialog box:

Options Steps
vCenter Client The vCenter Client list shows the name of the vCenter to which the VM is to be restored. You can only fail back to the vCenter for the original primary VM.
Proxy Client The proxy client is used only to browse the ESX server and datastore, and is not used to perform the failback operation. 

During a failback, the proxy that was specified for the original Live Sync schedule performs the backup, and the default proxy specified for the instance or subclient replicates the virtual machine to the primary site.

vCenter Instance Details Displays the host name and user account for the vCenter client.
Restore in place Select this option to fail back to the original location for the primary VM. Clear the option to restore to a different ESX server or datastore.
Source VM and Disk Displays the name of the original primary VM, with any associated disks listed under each VM.
Destination VM By default, displays the name of the original primary VM. You can change the name.

If a VM with the same name exists at the specified location, the Live Sync operation fails unless you selected Unconditionally overwrite VM with the same name.

ESX Server If you cleared the Restore in place option, click in this column and select the destination ESX server for the failback operation.
Datastore Select a datastore to be used for virtual machine disks.
vCenter Options Select one or more rows; then click Configure and provide any of the following information for the selected virtual machines:
Edit Destination VM Name (only displayed when multiple VMs are selected)
  • Prefix:

    Enter a prefix to be added to the destination VM names for all selected virtual machines.

  • Suffix:

    Enter a suffix to be added to the destination VM names for all selected virtual machines.

Destination VM (only displayed when a single VM is selected)
You can change the name of the destination VM in this box.
ESX Server
Click ... to select a new destination ESX server for all selected virtual machines.
Select a destination datastore for all selected virtual machines.
Resource Pool
Click ... to select a destination resource pool for all selected virtual machines.
VM Folder
Click ... to select a destination folder for all selected virtual machines.
Network Settings
Click Add to change the network configuration for restored VMs.

In the Network Settings dialog box, you can map each network in the Source Network list to a network in the Destination Network list. These mappings enable restored VMs to connect to appropriate networks in the location where they are restored.

Select a network from the Source Network list or type the network name as it is displayed in the vSphere client. Select Any Network to create a default rule for network adapters that are not covered by another rule. 

If you select Not Connected for the Destination Network value, virtual machines are restored with network interfaces in disconnected state.

IP Address settings
If a source VM running Windows uses a static IP address, you can configure an IP address for the destination VM:
  1. Click Add to display the IP Address settings dialog box.
  2. Enter the IP Address, Subnet Mask, and Default Gateway for the source VM.
  3. Use one of the following methods to specify settings for the destination VM:
    • Select Use DHCP to enable an available IP address for the specified network connection to be assigned automatically.
    • Enter values for the IP Address, Subnet Mask, and Default Gateway to identify the desired IP address mappings for the destination VM. You can also specify preferred and alternate DNS servers and WINS servers.

For more information, see IP Address settings.

You can also configure destination VMs directly in the Live Sync Options dialog box:

  • If the virtual machine is replicated to the same vCenter, enter a new name in the Destination VM column.
  • Select values for the ESX Server and Datastore columns. By default, virtual machine disks (VMDKs) for the destination VM are added to the same datastore where the source VM disks resided; but you can specify a different datastore.
Power ON Virtual Machine after restore Select this option to power on the virtual machine automatically after the restore operation completes.
Unconditionally overwrite VM with the same name Replace an existing virtual machine with the same name in the target location.

If the target VM is currently powered on, the failover or failback operation fails, regardless of the setting for this option.

Disk Provisioning Select the disk provisioning type for the destination VM: Original, Thick Lazy Zero, Thin, or Thick Eager Zero.

If the target VM already exists, this setting is ignored.