Backing Up Virtual Machines

You can back up virtual machines from a subclient or from a backup set (to include all subclients for the backup set). For each subclient, you must add the virtual machines to be backed up in the subclient content.

Before You Begin

  • Backups for virtual machines that contain a large number of files might take longer, because Commvault needs to break up large page ranges to ensure that pages can be read within the time limit that Azure Stack sets for reads. To improve the speed of backups, defragment disks that contain large numbers of files before performing the backup.
  • You can backup virtual machines configured with Azure Stack unmanaged and managed disks. From these backups, you can restore full virtual machines and restore guest files and folders.

    For restoring VMs from IntelliSnap backups: When executing a restore of a full VM configured with Azure Stack managed disks, because of a Microsoft Azure limitation, you can only restore the VM to the same Azure Region where the snapshot was created (the source of the snap copy used to restore the VM).

  • A current Microsoft Azure limitation prevents successful backup snapshots of Azure Stack virtual machine disks with 500 GB or more of data. During the backup process, Azure Stack is required to create a snapshot of each individual blob using Azure Stack API; however, with this limitation, the snapshot is failing. In order to protect these large virtual disks, use an in-guest agent. For more information, refer to File System Backup and Recovery.
  • For Azure volumes that were created by striping multiple blobs (virtual disks), it is recommended that you use an in-guest agent to protect the volume to ensure no loss of data. During the backup process, Azure is required to create a snapshot of each individual blob (virtual disk) in the volume using Azure API. These snapshots are taken consecutively (not simultaneously). If there is a time delay at any point during these operations, there is a possibility of data loss. To use an in-guest agent to protect the volume, refer to File System Backup and Recovery.


  1. From the CommCell Browser, expand Client Computers > virtualization_client > Virtual Server > Azure Stack > backup_set.
  2. Start the backup from the subclient or backup set:
    • From the subclient, right-click the subclient and click Backup.
    • From the backup set, right-click the backup set and click Backup All Subclients; then click Yes to confirm.
  3. In the Backup Options dialog box, choose the backup type.
  4. Optional: To schedule the backup, click Schedule.

    For more information on scheduling, see Scheduling.

  5. Optional: To further customize the backup operation, click Advanced.

    For more information about advanced options, see Advanced Backup Options.

  6. Optional: To save the current backup options as a script file, click Save as Script.

    For more information, see Save as Script Overview.

  7. Click OK to start the backup job.

    The VSA proxy coordinator assigns virtual machines to proxies for backup using round-robin logic.

You can track the progress of the job from the Job Controller. When the backup is complete, the Job Controller displays Completed.

After your backup job is complete, you can view the backup job history. For more information, see Job History.

Last modified: 4/17/2019 3:15:00 PM