In most cases, a VM works not alone but in cooperation with other services and components. To verify such VM, you first need to start all services and components on which this VM is dependent. To this aim, Veeam Backup & Replication uses the application group.
The application group creates the “surroundings” for the verified VM. The application group contains one or several VMs on which the verified VM is dependent. These VMs run applications and services that must be started to enable fully functional work of the verified VM. Typically, the application group contains at least a domain controller, DNS server and DHCP server.
When you set up an application group, you specify a role of every VM, its boot priority and boot delay. Additionally, you can specify what tests must be performed to verify VMs in the application group.
When a SureBackup job is launched, Veeam Backup & Replication first starts in the virtual lab VMs from the application group in the required order and performs necessary tests against them. This way, Veeam Backup & Replication creates the necessary environment for the verified VM. Only after all VMs from the application group are started and tested, Veeam Backup & Replication starts the verified VM in the virtual lab.
For example, if you want to verify a Microsoft Exchange Server, you need to test its functionality in cooperation with the domain controller and DNS server. Subsequently, you must add to the application group a virtualized domain controller and DNS server. When Veeam Backup & Replication runs a SureBackup job, it will first start and verify the domain controller and DNS server in the virtual lab to make verification of the Microsoft Exchange Server possible.
All VMs added to the application group must belong to the same platform — VMware or Hyper-V. Mixed application groups are not supported.