When deploying VMware Cloud Director Availability, by selecting the virtual appliance deployment type places the services of VMware Cloud Director Availability on dedicated cloud appliances, or on a combined appliance for testing purposes.

VMware Cloud Director Availability Appliance Services

VMware Cloud Director Availability services provide dedicated management interfaces for configuration and administration. The replication operations depend on the following services that run on each listed VMware Cloud Director Availability virtual appliances in the table.

Table 1. VMware Cloud Director Availability Services
Service Name Service Description
Replicator Service instances One or more service instances manage the vSphere Replication Server service and the LWD Proxy service and expose the low-level HBR primitives as a REST API. These instances operate with vCenter Server-level concepts, like virtual machines, folders, datastores.
The following VMware Cloud Director Availability appliances each run a single Replicator Service instance, depending on the cloud site:
  • Replicating with a multi-tenant VMware Cloud Director site:
    • Providers deploy multiple Cloud Replicator Appliance instances or a single Cloud Combined Appliance instance.
    • Tenants deploy On-Premises to Cloud Director Replication Appliance
  • vSphere DR and migration between vCenter Server sites:
    • Providers deploy vCenter Replication Management Appliance
    • Tenants deploy On-Premises to Cloud vCenter Replication Appliance
Manager Service A service that operates with vCenter Server-level concepts for managing the replication workflow and manages the Replicator Service instances by using REST API calls.
The following VMware Cloud Director Availability appliances each run the Manager Service instance, depending on the cloud site:
  • Replicating with a multi-tenant VMware Cloud Director site:
    • Providers deploy Cloud Replication Management Appliance or Cloud Combined Appliance.
  • vSphere DR and migration between vCenter Server sites:
    • Providers deploy vCenter Replication Management Appliance
    • Tenants deploy On-Premises to Cloud vCenter Replication Appliance
Cloud Service A service that operates with VMware Cloud Director-level concepts, like vApps and virtual machines. Manages the Manager Service by using REST API calls.
The following VMware Cloud Director Availability appliances each run the Cloud Service instance:
  • Replicating with a multi-tenant VMware Cloud Director site:
    • Providers deploy Cloud Replication Management Appliance or Cloud Combined Appliance.
Tunnel Service A service that orchestrates a secure tunnel creation and as a single endpoint channels both the incoming and outgoing site traffic, and both management data and replication data traffic using Lightweight Delta Protocol (LWD).
The following VMware Cloud Director Availability appliances each run the Tunnel Service instance, depending on the cloud site:
  • Replicating with a multi-tenant VMware Cloud Director site:
    • Providers deploy Cloud Tunnel Appliance or Cloud Combined Appliance.
    • Tenants deploy On-Premises to Cloud Director Replication Appliance
  • vSphere DR and migration between vCenter Server sites:
    • Providers deploy vCenter Replication Management Appliance
    • Tenants deploy On-Premises to Cloud vCenter Replication Appliance
Table 2. Replication Services
Service Name Service Description
vSphere® Replication™ Service with vSphere Replication filter The vSphere Replication Service, also called the HBR Service manages low-level replication operations, creates replication instances, and others. Receives and records the delta information for each replicated workload. During replication, only the delta information is sent from the source site ESXi host to the destination site ESXi host.
In a site, vSphere Replication Server operates in the following VMware Cloud Director Availability appliances:
  • Each Cloud Replicator Appliance instance or the single Cloud Combined Appliance instance
  • On-Premises to Cloud Director Replication Appliance
  • On-Premises to Cloud vCenter Replication Appliance
  • vCenter Replication Management Appliance
Lightweight Delta Protocol Service (LWD Proxy) A proprietary replication protocol service that manages the encryption, compression, and traffic monitoring of the replication traffic. Verifies that each incoming replication data stream comes only from the authorized source LWD Proxy instance. Also verifies that each outgoing replication data stream goes only to an authorized destination LWD Proxy instance.
In a site, LWD Proxy operates in the following VMware Cloud Director Availability appliances:
  • Each Cloud Replicator Appliance instance or the single Cloud Combined Appliance instance
  • On-Premises to Cloud Director Replication Appliance
  • On-Premises to Cloud vCenter Replication Appliance
  • vCenter Replication Management Appliance
VMware Cloud on AWS Data Engine Service (Data Engine Service) A new service, introduced with VMware Cloud Director Availability 4.2 for performing migrations to VMware Cloud on AWS by using the new VMC replication data engine, due to the design specifics of the Cloud Director service. By using the Data Engine Service and with the VMC data engine selected, VMware Cloud Director Availability migrates workloads to Cloud Director service.

For information about migrating to VMware Cloud on AWS, see Migration to VMware Cloud Director service in the Migration to VMware Cloud Director service Guide.

In a site, a Data Engine Service instance operates in the following VMware Cloud Director Availability appliances:
  • Each Cloud Replicator Appliance instance or the single Cloud Combined Appliance instance
  • On-Premises to Cloud Director Replication Appliance
The following services run on all VMware Cloud Director Availability appliances.
Table 3. Other Services
Service Name Service Description
sshd A standard Linux service that provides Secure Shell (SSH) access on port 22 to the VMware Cloud Director Availability appliances. By default, this service is inactive. After explicitly enabling SSH during deployment or in the management interface, this service activates and starts. Only the root user is allowed to authenticate. Three unsuccessful login attempts lock the root user account for 15 minutes.
systemd-timesyncd A standard Linux service that provides NTP time management. To configure an NTP server, use the management interface. This service is constantly running.
vaos A VMware service for guest OS initialization, operating VMware infrastructure settings. For example, network settings, hostname settings, creating SSH keys, running boot scripts, accepting EULA, and others. This service runs during the appliance boot.
h4postgresql An embedded PostgreSQL server, that only listens on the local loopback device. You cannot use an external database and you cannot expose the embedded database externally. This service is constantly running.

Network Ports

For information about the network ports required for the correct operation of VMware Cloud Director Availability, see VMware Cloud Director Availability - VMware Ports and Protocols.

For information about the services connectivity, see Services Network Connectivity.

For information about the network requirements and the external interfaces between the paired sites of VMware Cloud Director Availability, select your version and see: