A replication tracking virtual machine (RT VM) represents a shadow VM for replication placement that allows per-disk placement. An RT vApp is a vApp that consists of RT VMs. As a provider, you can configure the placement solution of the existing vApp and VM replications to RT VM.

Since VMware Cloud Director Availability 4.7, when using a supported version of VMware Cloud Director in the destination site, then RT VM replaces the independent disk as the placement and reporting solution going forward.

RT VM is a shadow VM residing in the destination VMware Cloud Director that represents the replication. Performing recovery promotes the shadow VM as the workload VM. This recovery process is faster and more robust, allowing for lower RTO. The RT vApp is composed at configuration time instead of recovery time. Also, the recoveries use reload from path, instead of registering a new VM in vCenter, allowing for better RTO and resilience.

A replication that uses RT VM allows placing the replica files in separate data stores for each disk and for the VM itself.

  • Independent disks remain supported for backwards compatibility with VMware Cloud Director 10.5 and earlier VMware Cloud Director Availability versions.
  • All new replications automatically use RT VM when using VMware Cloud Director 10.5.1 or later and VMware Cloud Director Availability 4.7 and later.
  • With VMware Cloud Director 10.5.1 in the destination site, it is recommended to configure replication tracking placement solution for all the existing replications.

Configure Replication Tracking

Note: Organization users cannot see nor interact with the RT VM itself in the inventory of VMware Cloud Director. These tenant users also do not see Replication Tracking as an option in VMware Cloud Director Availability.

After performing failover, test failover, or migration, then the workload VM becomes available for them in the destination site.

When supported by the version of VMware Cloud Director in the destination site, as a provider, you can configure RT VM placement solution for existing replications. This configuration of the placement solution completes quickly and is irreversible:
  • The replica files do not move across data stores during the configuration and the bandwidth is not affected.
  • Once configured as replication tracking, the placement solution of a replication cannot revert to independent disk.
  • The disk space consumption does not change after upgrading to RT VM.
  • All VMs in a vApp replication configure their placement solutions in parallel. vApp replications cannot be recovered when they have Mixed placement solutions, that is some of the VMs use Independent disk, while others use RT VM. To recover such vApp replication, all VM replications must be first configured with RT VM.
  • Only providers can see and configure the placement solution.
  • Both the source and the destination sites require VMware Cloud Director Availability 4.7 or later and VMware Cloud Director 10.5.1 or later in the destination site for the placement solution configuration.
To configure the placement solution for existing replications:
Note: Despite recommendations, for existing replications using the VMC data engine you cannot use All Actions > Configure Replication Tracking. New VMC data engine replications use RT VM placement solution. For information about the data engines, see Activate the data engines for replicating workloads in the Administration Guide.
  1. Log in to VMware Cloud Director Availability as a provider then in the left pane click either Incoming Replications or Outgoing Replications.
  2. To configure the existing replications, click the vApp tab or the VM tab then see the Placement solution column for each replication.
  3. Select one or more replications that show Independent disk then click All Actions > Configure Replication Tracking.

    All VMs in a vApp replication or in a vApp template replication must use the same placement solution. When you click All Actions > Configure Replication Tracking for a vApp replication, configure all of its VMs as replication tracking placement solution.

    Configure Replication Tracking remains inactive when not supported by the version of the destination site VMware Cloud Director.
  4. In the Configure Replication Tracking window, click Apply.
  5. Optionally, to monitor the progress of the placement solution configuration for the selected replications, in the left pane click Tasks.