Using a VM Agent

With NAKIVO Backup & Replication, you can install a permanent virtual machine agent (VMA) rather than injecting a temporary agent for every job run. This agent simplifies OS quiescing and file-level recovery to the source virtual machine by eliminating the need to provide credentials for the VM’s guest OS.


  • The VM agent is used for OS quiescing if the relevant job option is enabled and only for Hyper-V. For other hypervisors, VMA is used only for file recovery.

For information on VMA system requirements, see Feature Requirements. For information on installing a VMA, see Installing a VM Agent.

After installing a VM agent inside a VM and adding it to the Nodes tab, you may proceed with configuring it for use in jobs. See the sections below:

Setting Default Credentials

To configure a default master password for VM agents, do the following:

  1. Go to Settings > Inventory > Manage > Credentials.

  2. Click Add Credentials.

  3. In the Type drop-down list, select Master password.

  4. Enter a Name and Password.

  5. Optionally, add a Description.

Enabling VM Agents

To enable your installed VM agents (VMAs) to be used in jobs, proceed as follows:

  1. Click on a job containing the VM in which you have installed a permanent agent.

  2. Go to Manage > Edit > Options.

  3. Make sure that Use installed VM agents is enabled. Click settings.

  4. Click Scan All to scan every VM in the job for a VM agent.

  5. Once the scan is complete, select the master password you wish to use for the discovered VM agents from the Select credentials drop-down list.

  6. In the Certificate column, click Verify to verify the validity of a VMA’s certificate.

  7. Save the updated job options.

Repeat this process for all jobs for which you want to enable the use of VMAs.


  • If a VM agent is installed on the recovery server when creating or editing a File Recovery job, the installed agent will automatically be chosen to perform recovery operations.

  • If NAKIVO Backup & Replication cannot find installed VM agents or is prevented from doing so (such as by a firewall), the application will scan the VMs until a 2-minutes timeout. VMs are scanned in parallel.

  • If there is no VM agent at the target VM, you may proceed by providing OS credentials to the target machine.

How a VM Agent Works

When supported VM actions are prompted, the Director checks for VM agent availability on the respective VM as follows:

  1. If an installed VMA is found in the VM, the Director uses this VMA to perform the specified action(s).

  2. If an installed VMA is not found in the VM, the Director injects a temporary agent or uses native tools (for example, VMware Tools) to perform the specified action(s). You must then enter VM credentials to proceed.

  3. If the usage of an installed VMA is disabled in job options, the Director uses the injection approach or native tools to proceed.