This section describes the core architecture of the vCloud Availability service.

vCloud Availability is a Disaster Recovery-as-a-Service (DRaaS) solution that provides simple and secure asynchronous replication and failover for vSphere managed workloads. The service operates through a VMware vCloud® Air™ Network Service Provider, and each installation provides recovery for multiple tenants. The service provides the following features:

  • Self-service protection, failover, and failback workflows per virtual machine

  • Recovery point objective (RPO) from 15 minutes to 24 hours

  • Initial data seeding by shipping a disk

For the service provider,vCloud Availability:

  • Integrates with existing vSphere environments

  • Multi-tenant support

  • Built-in encryption of replication traffic

  • Supports multiple vSphere versions

  • Supports multiple ESXi versions

  • Individual systems are isolated as virtual machine files

  • Full integration with the vCenter Server Web client

  • Automation provided through standard Web service APIs

Failover from on-premises to Cloud

Replicates data from on-premises vSphere workloads to service provider cloud environments. After the virtual machines are replicated, failover support for running the workloads in the cloud. Recovery Point Objective (RPO) can be configured from 15 minutes to 24 hours.

Fail back to on-premises

For failover loads that have been migrated to the cloud, changes can be replicated back to the on-premise environment. You can then failback workloads in the on-premise environment.

Multiple Points In Time (MPIT) Recovery

Up to 24 restore points can be created. Depending on the RPO configuration, restoration is available from any recovery point.


Using VMware vRealize® Orchestrator™ Appliance and plug-in for vSphere Replication you can easily design and deploy scalable workflows that automate complex IT processes.


The architecture of the solution relies on the service provider environment that provides the replication target and the customer, or tenant, environment that employs vSphere Replication to move the data to the service provider. In the service provider environment, multiple components operate together to support replication, secure communication, and storage of the replicated data. Each service provider can support recovery for multiple customer environments that can scale to handle increasing loads for each tenant, and for multiple tenants.

On the tenant side, a single VM instance is deployed in the tenant vSphere environment. This deployment provides management service that is used to oversee the replication operation for each replicated VM. Standard vSphere Replication is used to exchange this information with the service provider infrastructure.

The gray cells in the following diagram represent existing components in the service provider and tenant environments. The remaining colored cells represent vCloud Availability components that you deploy during vCloud Availability Installation and Configuration procedures.

Table 1. vCloud Availability Component Definitions.


Abbreviation/Internal Name


vSphere Replication Cloud Service


A tenant-aware replication manager that provides the required API for managing the service and all the components. vSphere Replication Cloud Service registers as a VMware vCloud Director® extension enabling the functionality through the existing vCloud Director API.

vSphere Replication Manager


The management server manages and monitors the replication process from tenant VMs to the service provider environment. A vSphere Replication Management Server runs for each vCenter Server and tracks changes to VMs and infrastructure related to replication.

vSphere Replication Server


The replication server receives and records delta information for each replicated VM. During to-cloud replication, delta information is sent by the tenant ESXi host and recorded by the provider vRS. During from-cloud replication, delta information is sent by the provider ESXi host and recorded by the tenant vSphere Replication Server.

vCloud Tunneling Agent


vCTA is a software component which supports tunneling functionality at the on-premise data center. vCTA is responsible for orchestrating a secure tunnel creation for both to-the-cloud and from-the-cloud tunnels.

vCloud Director


With the vCloud Director solution service providers can build secure, multi-tenant private clouds by pooling infrastructure resources into virtual data centers and exposing them to users through Web-based portals and programmatic interfaces as fully automated, catalog-based services.

Cloud Proxy


Provides the vCloud Director endpoint for tunnels use to replicated data from on-premises vCTA to and from vCloud Director.

Management vCenter Server


The Management vCenter Server environment is managed by the service provider and not accessible for tenants.

Resource vCenter Server


The Resource vCenter Server is a vCenter Server registered to vCloud Director and made available to tenants. Tenants do not have direct access to the Resource vCenter Server environment. Tenants can only locate workloads on the Resource vCenter Server instances using vCloud Director.

Tenant vCenter Server


The Tenant vCenter Server environment is used solely by the tenant users and is not connected to vCloud Director.

VMware Platform Services Controller™


The Platform Services Controller provides common infrastructure services to the vSphere environment. Services include licensing, certificate management, and authentication with VMware vCenter ®Single Sign-On.



Cassandra is used to store metadata about the replication, replicated VM instances, and infrastructure elements required to support the service. Cassandra is used as a fault-tolerant datastore.



An open source message broker that implements the Advanced Message Queuing Protocol (AMQP).

When vSphere Replication Cloud Service registers as a vCloud Director extension, RabbitMQ is used to exchange information with vCloud Director.



The locator must be a valid path to be used with the VMware OVF Tool, as shown in the following examples.

  • /datacenter-name/host/esx-name

  • /datacenter-name/host/cluster-name



The name of a vSphere datastore, accessible by the locator.