Introduction to Screenshot Verification
Topic
This article explains the Screenshot Verification feature of SIRIS and ALTO devices and gives resources to troubleshoot failed screenshot errors. For more information about the mechanics of virtualizations on Datto appliances, and how they relate to screenshot verification, see the How Virtualizations Work article.
Environment
- Datto SIRIS
- Datto ALTO
Description
Screenshot Verification confirms that your Datto device's backups are healthy and working. This feature automatically builds and boots virtual machines from preexisting backups and performs context-sensitive tests against the virtual machine's output to evaluate a pass or fail state. You can configure Screenshot Verification on the Configure Agent Settings page of the Datto appliance GUI.
This article focuses on common problems that you can resolve through these configurable options.
Your Datto device can be configured to send email alerts detailing the results of the Screenshot Verification process.
IMPORTANT Screenshot verification confirms the ability of a virtualization to boot the operating system of the protected system. It does not test the viability of non-boot volumes. You can use Local Verification to check non-boot volumes.
Note that Datto devices on IRIS 4.0 or newer will automatically initiate a differential merge backup after five failed screenshot attempts as long as a successful screenshot has been completed for the asset within the last month. A differential merge backup may resolve some errors that cause screenshots to fail.
Limitations
Due to a limitation of the libvirt virtualization API, if an agent-based protected system's hostname is 50 characters in length or more, or an agentless protected system's name is 42 characters or more, screenshot verification will fail.
Diagnosing Screenshot Verification failures
If the screenshot verification process does not detect a successful boot, it will simply capture an image of the screen after a preset amount of time.
You can view the results of a screenshot verification by logging into the Datto GUI, clicking the PROTECT tab, and then clicking Manage Recovery Points. Place your cursor over the circle under the Screenshot Verification column for the date and time you wish to view.
Figure 1: Successful screenshot
When diagnosing a failed screenshot, the captured image may not display the correct error or state that caused the failure. To check, create a virtual machine manually through the Datto device GUI to observe its behavior.
Creating a virtual machine manually
To create a virtual machine manually, follow the steps below.
NOTE Local virtualizations are not available on ALTO devices.
- Log in to the Datto device GUI.
- Click Restore.
- Select the protected machine to be virtualized by clicking the corresponding button under Start aRestore.
- Under Choose Recovery Type, select Local Virtualization.
- Under Choose a Recovery Point, select the same point in time for which the screenshot failed.
- After confirming the information is correct, click START RESTORE.
Figure 2: Setting up a local virtualization
- On the Local Virtualization screen (Figure 3), you can set the following:
- Number of CPU cores
- The amount of RAM
- Storage Controller
- Network Options
- Video Controller
Figure 3: Local virtualization settings
To replicate the exact behavior of the virtual machine during screenshotting, select the same amount of virtualization resources and the same storage controller used by the screenshot verification process. By default, screenshots for 32-bit virtual machines use 1 CPU core and 2 GB (2048MB) of RAM, and screenshots for 64-bit systems use 2 CPU cores and 3 GB (3072MB) of RAM. The screenshot verification process uses whichever storage controller you set in the Configure Agent Settings screen for the desired agent.
For testing purposes, set Network Options to Disconnected and uncheck the box labeled Create Rescue Agent. For more information about the different options, check out Remote Web - Local Virtualization - Local Options.
- After confirming the resources and storage controller, start the virtual machine: by clicking Start VM.
- Observe its behavior by downloading the automatically-generated RDP link.
NOTE RDP access to virtualizations requires the connecting workstation to be running Windows Server 2008 SP3 or newer.
- After testing, stop and unmount the virtual machine through the Restore menu. Automated screenshots will not occur if a virtual machine is already mounted.
