To interact with the VM guest OS during the backup or replication job, Veeam Backup & Replication needs to deploy a runtime process in each VM. Guest OS interaction is performed if you enable the following options in the job:
- Application-aware processing
- Guest file system indexing
- Transaction logs processing
Previously, the runtime process on all VMs was deployed by the backup server. This could cause the following problems:
- The load on the backup server was high.
- If a connection between two sites was slow, the job performance decreased.
- If the backup server had no connection to VMs, application-aware processing tasks were not accomplished for these VMs.
The task of deploying the runtime process in a Microsoft Windows VM is performed by the guest interaction proxy. The guest interaction proxy is a backup infrastructure component that sits between the backup server and processed VM. The guest interaction proxy deploys the runtime process in the VM and sends commands from the backup server to the VM.
The guest interaction proxy allows you to communicate with the VM guest OS even if the backup server and processed VM run in different networks. As the task of runtime process deployment is assigned to the guest interaction proxy, the backup server only has to coordinate job activities.
The guest interaction proxy deploys the runtime process only in Microsoft Windows VMs. In VMs with another guest OS, the runtime process is deployed by the backup server.
You can use multiple guest interaction proxies to improve performance. Multiple guest interaction proxies will deploy runtime processes in VMs faster compared to the same operation performed by one guest interaction proxy.
In a backup infrastructure with multiple remote sites, you can deploy a guest interaction proxy in each site. This can reduce load on the backup server and produce less traffic between the backup server and remote site. The backup server will only have to send commands to the guest interaction proxies.
Requirements for Guest Interaction Proxy
To perform the role of guest interaction proxy, the machine must meet the following requirements:
- It must be a Microsoft Windows machine (physical or virtual).
- You must add it to the Veeam Backup & Replication console as a managed server.
- It must have either a LAN or VIX connection to the VM that will be processed. You do not have to set up both connections — only one connection is required. For more information about setting up a connection to the VM, see https://www.veeam.com/kb1788.
The guest interaction proxy role can be performed by any machine that meets the requirements, including backup proxy, backup repository, WAN accelerator or backup server.
The guest interaction proxy functionality is available in the Enterprise and Enterprise Plus Editions of Veeam Backup & Replication.
Guest Interaction Proxy Selection
When you add a Microsoft Windows machine to the backup infrastructure, Veeam Backup & Replication deploys the Data Mover Service on it. The Data Mover Service includes the components responsible for runtime process deployment during guest OS interaction.
To assign a guest interaction proxy for the job, you must select a Microsoft Windows machine that will perform the role of the guest interaction proxy at the Guest Processing step of the backup or replication job wizard. You can assign the guest interaction proxy manually, or let Veeam Backup & Replication do it automatically. Veeam Backup & Replication uses the following priority rules to select the guest interaction proxy:
- A machine in the same network as the protected VM that does not perform the backup server role.
- A machine in the same network as the protected VM that performs the backup server role.
- A machine in another network that does not perform the backup server role.
- A machine in another network that performs the backup server role.
If Veeam Backup & Replication finds several available machines of equal priority, it selects the less loaded machine. The load is defined by the number of tasks that the machine already performs.
Failover from Guest Interaction Proxy to Backup Server
If the guest interaction proxy fails to connect to a Microsoft Windows VM, the guest interaction proxy will not be able to access the VM and deploy a runtime process in it. In this case, the backup server will take over the role of guest interaction proxy and deploy the runtime process in the VM.