In the VMware Cloud Director Availability Tenant Portal or in the VMware Cloud Director Availability vSphere Client Plug-In, you can protect or migrate workloads by replicating vApps or virtual machines.

Protect or migrate vApps and virtual machines by replicating the workload from one site to another. The replications can be incoming to the site, or outgoing from the site.

Replication Types

Migration
Migrating a vApp or a virtual machine to a remote organization runs the workload in the destination site.
Protection
Protecting a vApp or a virtual machine from one organization to another keeps the workload running in the source site.

From VMware Cloud Director Availability 4.1 and later, the service provider separately enables migrations and protections in the replication policies either only incoming or only outgoing, or both, or neither. In previous versions, the service provider controls both replication types together, as incoming replications or outgoing replications.

In a newly deployed VMware Cloud Director Availability 4.1 or later, by default:
  • Migrations are allowed, both incoming and outgoing, in the default replication policy to get more workloads with migration available for everyone.
  • Protections are disabled, both incoming and outgoing, in the default replication policy. To enable the site for protections, the service provider must modify the default policy. Alternatively, keep DR only for subscribers by assigning a custom policy to the organizations. For more information, see Configuring Replication Policies.

After upgrading from a previous version, replication policies with enabled incoming replications now have enabled incoming migrations and enabled incoming protections. Policies before the upgrade with disabled incoming replications now have disabled incoming migrations and disabled incoming protections. Similarly, the previous outgoing replications now control the outgoing migrations and outgoing protections.

VMware Cloud Director Availability 4.1 and later sites interpret previous versions of paired sites with enabled replications as enabled both migrations and protections. For information about pairing sites with mismatching versions, select the latest VMware Cloud Director Availability site version in Managing Connections Between Cloud Sites in the VMware Cloud Director Availability Administration Guide.

Recovery Point Objective - RPO

The RPO is the longest tolerable time frame of data loss. For example, with one hour RPO the recovered virtual machine can have no more than one hour of data lost. Shorter RPO intervals, ensure less data loss during recovery, at the expense of consuming more network bandwidth to keep the replica up to date.

When each virtual machine reaches its RPO target, the Replicator Service writes about 3800 bytes in the vCenter Server events database. Low RPO values, increase the volume of event data in the database. You can limit the number of days that vCenter Server retains event data, or set a longer RPO value to reduce the volume of event data.

Note: Migrations RPO, by default is 24 hours.

Quiescing

The Replicator Service guarantees a failure consistency among all disks in a virtual machine. Enabling quiescing might obtain a higher level of failure consistency among the disks that belong to a virtual machine. The operating system of a virtual machine determines the available quiescing types. Quiescing is available only for virtual machine operating systems that support quiescing. For more information, see Guest OS Quiescing Support in the vSphere Replication documentation.

Replicated Workload Settings

VMware Cloud Director Availability preserves and periodically synchronizes the VMware Cloud Director settings that accompany the vApps or the virtual machines in a replication. After a successful protection or migration, VMware Cloud Director Availability reads these settings from the source site and applies them to the destination site, at the end of the replication workflow.
Table 1. Replicated vApp Settings
vApp Settings Replicated in Version 3.0 Replicated in Version 3.5 or Later
vApp Name Yes Yes
Description Yes Yes
Leases - -
Starting and Stopping VMs Configuration - -
Мetadata Yes Yes
vApp Networks - Yes
Table 2. Replicated VM Settings
VM Settings Replicated in Version 3.0 Replicated in Version 3.5 or Later
VM Name Yes Yes
Computer name Yes Yes
Description Yes Yes
Hot add settings - -
Guest OS Customization - Yes
Guest properties - Yes
Resource allocation - -
Metadata Yes Yes
Attention: Before performing a failover or a test failover, by default the active option in VMware Cloud Director - VM discovery must be deactivated. For information about deactivating virtual machine discovery, select the VMware Cloud Director version in Discovering and Adopting vApps in the VMware Cloud Director documentation.

Modifying the Hardware of a Source Virtual Machine While Protected by VMware Cloud Director Availability

  • Adding another virtual disk to a replicated virtual machine at the source site pauses the replication.
  • VMDK resizing with vSphere 7.0 in the source site automatically resizes the protected virtual machine disk in the destination site, retaining the replication instances.
  • Modifying the vCPU count or the RAM size of the source virtual machine replicates on RPO or on manual synchronization in the destination site.

Replicating Thin or Thick Provisioning Virtual Disks

The replicated disks provision format depends whether using replication seeding. For information about seeds, see Using Replication Seeds.
  • If not using replication seed, the replica disks are always thin provisioned.
  • If using replication seed, the replica disks depend on the seed.
    • If the replication seed is thick-provisioned, the replica disks are provisioned as thick.
    • If the replication seed is thin-provisioned, the replica disks are provisioned as thin.

Replicating Other Storage

Storage DRS (SDRS)
  • At the protected site, storage DRS is supported.
  • At the recovery site, storage DRS does not move replication files between datastores. Datastore maintenance mode, storage balancing, and IO balancing all ignore replication files. The only supported way to move the replication files between datastores is to change the storage policy.
Raw Device Mapping (RDM)
  • RDMs in virtual compatibility mode can be protected.
  • RDMs in physical compatibility mode are skipped from replication.
Multi-Writer Disks
VMware Cloud Director Availability does not support disks in multiwriter mode.
Independent Disks
VMware Cloud Director Availability does not migrate independent disks.
Change Block Tracking (CBT)

VMware Cloud Director Availability instances are not compatible with CBT. For information about the instances, see Using Instances.