To perform most data protection and disaster recovery operations (such as creating image-level backups and restoring backed-up data from them), Veeam Backup for Nutanix AHV uses workers. Workers are Linux-based VMs that are responsible for the interaction between the backup appliance and other Veeam Backup for Nutanix AHV components. Workers process backup workload and distribute backup traffic when transferring data to backup repositories.
By default, the worker role is assigned to the backup appliance. However, this is sufficient only for small deployments with low traffic load. For large deployments, it is recommended to deploy dedicated workers as the embedded worker may not have enough bandwidth to process backup traffic. Deploying dedicated workers allows you to increase the maximum number of concurrent backup and restore operations, and to avoid high traffic load on the host running the backup appliance.
Each dedicated worker is launched on a specific host for the duration of a backup or restore operation. While configuring the worker, you can manually select the host or instruct Veeam Backup for Nutanix AHV to choose a host automatically. Manual selection may be helpful if you want to avoid launching workers on specific hosts (for example, production ones), while automatic selection allows Veeam Backup for Nutanix AHV to optimize data transfer and to balance the load on the hosts in the Nutanix AHV cluster. In the latter case, Veeam Backup for Nutanix AHV uses the AHV affinity functionality to distribute workers among all hosts in the cluster instead of launching multiple workers on one host.
When you add a dedicated worker to the backup infrastructure, its configuration is saved to the Veeam Backup for Nutanix AHV configuration database, but no VM is actually deployed in the cluster unless you choose to test the configuration. In the latter case, a VM (worker VM) is deployed and shut down after the test operation completes.
As soon as a backup or restore session starts, Veeam Backup for Nutanix AHV tries to launch the worker and test its configuration. If no worker VM has been previously deployed, Veeam Backup for Nutanix AHV deploys the VM using the worker configuration saved to the configuration database. Veeam Backup for Nutanix AHV checks host affinity settings specified for the worker and chooses a host where the worker VM will run. Then, Veeam Backup for Nutanix AHV powers on the worker VM and installs system updates (if available). When the backup or restore session completes, Veeam Backup for Nutanix AHV shuts down the worker VM so that it can be used for other sessions later.
During the lifecycle, a worker can obtain one of the following statuses:
- Configured — the worker configuration is added to the Veeam Backup for Nutanix AHV configuration database.
- Testing — the worker configuration is being tested.
- Updating — the worker or its configuration is being updated.
- Working — the worker is processing a backup or restore operation.
- Shut Down — the worker is powered off.
- [Applies only to the embedded worker] Ready — the worker is powered on and can be used for data protection operations.