Worker Instances

A worker instance is an auxiliary Linux-based virtual machine that is responsible for the interaction between the backup appliance and other Veeam Backup for Microsoft Azure components. Worker instances process backup workload and distribute backup traffic when transferring data to backup repositories.

Worker Instance Components

A worker instance uses the following services:

  • Veeam Data Mover — the service that performs data processing tasks. During backup, the Veeam Data Mover service retrieves source data to backup repositories. During restore, the Veeam Data Mover transfers backed-up data from backup repositories to the target location.
  • File-level recovery browser — the web service that allows you to find and save files and folders of a backed-up Azure VM to a local machine or to the original Azure VM. The File-level recovery browser is installed automatically on every worker instance that is launched for file-level recovery.

For more information on recovering files of Azure VMs using the File-level recovery browser, see Performing File-Level Recovery.

Note

By design, Veeam Backup for Microsoft Azure installs the unattended-upgrades package on every launched worker instance. This package automatically sends requests to the Ubuntu Security Update repository (security.ubuntu.com) to get and install security updates on the worker instance. To reconfigure or disable these updates, open a support case.

Security Certificates for Worker Instances

Veeam Backup for Microsoft Azure uses self-signed TLS certificates to establish secure communication between the web browser on a user workstation and the File-level recovery browser running on a worker instance during the file-level recovery process. A self-signed certificate is generated automatically on the worker instance when the recovery session starts.

How Worker Instances Work

Veeam Backup for Microsoft Azure automatically launches worker instances to process Azure VMs and Azure SQL databases when performing a backup or restore operation, and keeps the instances running for the duration of the operation. Veeam Backup for Microsoft Azure launches one worker instance per each Azure resource specified in a backup policy or restore task. To minimize cross-region traffic charges and to speed up the data transfer, depending on the performed operation, Veeam Backup for Microsoft Azure launches worker instances in the following locations:

Operation

Worker Instance Location

Default Worker Instance Size

Creating image-level backups of Azure VMs

Azure region in which a processed Azure VM resides

Standard_F2s_v2, 2 CPU, 4 GB RAM

Creating backups of Azure SQL databases

Azure region in which a SQL Server hosting the processed database resides

Azure file share indexing

Azure region in which a processed file share resides

Creating archived image-level backups of Azure VMs

Azure region in which an archive backup repository storing backed-up data resides

Standard_E2_v5, 2 CPU 16 GB RAM

Creating archived backups of Azure SQL databases

Azure region in which an archive backup repository storing backed-up data resides

Performing health check for created restore points

Azure region in which a target backup repository resides

Standard_F2s_v2, 2 CPU, 4 GB RAM

Applying retention policy settings to created restore points

Azure region in which a backup repository with backed-up data resides

Restoring Azure VMs and Azure SQL databases

Azure region in which the restored Azure VM or SQL Server hosting the restored database resides

Restoring individual virtual disks of Azure VMs

Azure region in which the restored virtual disk resides

File-level restore from cloud-native snapshots

Azure region in which a cloud-native snapshot resides

File-level restore from image-level backups

Azure region in which a backup repository storing backed-up data resides

Worker instances are launched based on worker configurations and profiles. For more information, see Managing Worker Instances.

Requirements for Worker Instances

By default, Veeam Backup for Microsoft Azure creates a new network configuration for each Azure region in which it launches worker instances. However, you can add custom worker configurations to provide network settings that will be used to launch worker instances in a specific region. In this case, for every Azure region where worker instances will be launched, you must specify a virtual network and a subnet to which the worker instances will be connected. You can also specify a security group that will be associated with the specified subnet. To learn how to configure network settings for worker instances, see Adding Worker Configuration.