Validation methods

In a validation plan, the following validation methods are available:

  • Checksum verification
  • Run as virtual machine
    • VM heartbeat
    • Screenshot validation

Checksum verification

Validation via checksum verification calculates a checksum for every data block that can be recovered from the backup, and then compares it against the original checksum for that data block, which was written during the backup process. The only exception is validation of file-level backups that are located in the cloud storage. These backups are validated by checking the consistency of the metadata saved in the backup.

Validation via checksum verification is a time-consuming process, even for an incremental or a differential backup, which are small in size. The reason is that the validation operation checks not only the data that is physically contained in a particular backup, but all of the data that needs to be recovered – that is, previous backups might also need to be validated.

A successful validation via checksum verification means a high probability of data recovery. However, the validation via this method does not check all factors that influence the recovery process.

If you back up an operating system, we recommend that you use some of the following additional operations:

Run as virtual machine

This method works only for disk-level backups that contain an operating system. To use it, you need an ESXi or Hyper-V host and a protection agent (Agent for VMware or Agent for Hyper-V) that manages this host.

The Run as virtual machine validation method is available in the following variants:

  • VM heartbeat

  • Screenshot validation

You must select at least one of them.

VM heartbeat

With this validation method, the agent runs a virtual machine from the backup, connects to VMware Tools or Hyper-V Integration Services, and then checks the heartbeat response to ensure that the operating system has started successfully. If the connection fails, the agent attempts to connect every two minutes, a total of five times. If none of the attempts are successful, the validation fails.

Regardless of the number of validation plans and validated backups, the agent that performs validation runs one virtual machine at a time. As soon as the validation result becomes clear, the agent deletes the virtual machine and runs the next one.

Use this method only when you validate backups of VMware virtual machines by running these backups as virtual machines on an ESXi host, and backups of Hyper-V virtual machines by running them as virtual machines on a Hyper-V host.

Screenshot validation

With this validation method, the agent runs a virtual machine from the backup, and while the virtual machine is booting, screenshots are made. A machine intelligence (MI) module checks the screenshots and if there is a login screen on them, it marks the backup as validated.

The screenshot is attached to the recovery point and you can download it in the Cyber Protect console within one year of the validation. For more information on how to check the screenshot, refer to Checking the validation status of a backup.

If notifications are enabled for your user account, you will receive an email about the validation status of the backup, in which the screenshot is attached. For more information about the notifications, refer to Changing the notification settings for a user.

Screenshot validation is supported by agent version 15.0.30971 (released in November, 2022) and later.

Screenshot validation works best with backups of Windows and Linux systems with GUI-based login screen. This method is not optimized for Linux systems with console login screen.