Skip to main content

How can we help you?

Druva Documentation

Hyper-V FAQs

Enterprise Workloads Editions: File:/tick.png Business File:/cross.png Enterprise File:/tick.png Elite


Can I back up virtual machines that are hosted on an Azure Stack HCI cluster? 

What types of deployments are available in Hyper-V?
You can deploy virtual machines that are hosted on Windows servers and Microsoft Azure Stack HCI.

I removed data from my disks to optimize storage I use on Druva. I haven't added a file but I see a considerable change in Source+Data. What does it mean?

Druva detects a change even if you remove data from your disks. For example, Druva backed up 100 GB of data from your virtual machine. Later on, you removed 25 GB of data and Druva runs another backup for your virtual machine. The Source+Change section shows 125 GB because Druva detects a 25 GB modification on the virtual machine. However, you are not charged for 125 GB. You are charged only for the storage you consume. The Source+Change only shows a chart that indicates the data modified on your server.

Why is the host field blank for some of the FLR proxies that I registered?

If you deploy an FLR proxy virtual machine to a Windows Server 2008 or Windows Server 2008 R2 host, Druva cannot list its host since Guest integration service is not available for Hyper-V 2008 hosts. 

Why do I see a different name on the Management Console when I created the FLR proxy virtual machine with a different name on the host?

If you deploy the FLR proxy on a Windows Server 2008 or Windows Server 2008 R2 host, Druva registers the FLR proxy with the virtual machine's guest operating system's hostname. By default, the guest operating system hostname is FLRProxy, and you have login to the FLR proxy virtual machine, manually change its hostname, and reboot the FLR proxy virtual machine to update its name on the Management Console. 

How do I configure Druva to use third party VSS providers? 

  1. From the command prompt, run the following command:
    vssadmin list providers

    Running this command displays a list of VSS providers, and the provider IDs. 

  2. Stop the Hybrid Workloads agent service. 
  3. Open the Phoenix.cfg file in a text editor. 
    The Phoenix.cfg file is available at the following location:
    Windows 2012 and 2008: C:\ProgramData\Phoenix
  4. Add the VSS_PROVIDER_ID_VOLUMES parameter, and set its value to reflect the drives for which you want the Hybrid Workloads agent to recognize the third-party VSS provider that you configured. 
    Use the following format:
    VSS_PROVIDER_ID_VOLUMES = {"<Drive>": "{<Provider ID>}", "Drive": "{<Provider ID>}"}
    For example, if you want to set VSS providers for C drive, E drive, and the cluster shared volume, the parameter looks like the following:
        "C:\\" : "{b5946137-7b9f-4925-af80-51abd60b20d5}",
        "E:\\" : "{24602736-bed9-4619-91b0-243447c6409c}",
        "C:\\ClusterStorage\\Volume1\\" : "{b5946137-7b9f-4925-af80-51abd60b20d5}",

     For a clustered shared volume, add a double backslash (\\) at the end of the UNC path that you specify (as shown in the example above).

  5. Save the Phoenix.cfg file.
  6. Start the Hybrid Workloads agent service. 

Why is complete disk image uploaded when backing up VMs with dynamic disk

This is an expected behavior, the backup mechanism for Hyper-V uses resilient change tracking (RCT) and only uploads the allocated data. The remaining sparse blocks get uploaded only for the first backup and do not consume any storage. The data displayed under Current source on the dashboard displays the maximum size of the disk.

How does backing up a VM configured with Dynamic disk affect credit consumption?

Druva uploads data after normalizing as per 1MB block-size, only the allocated disk size would consume credits and not the sparse blocks.

  • Was this article helpful?