Virtual machine backup workflow

Step 1

Virtual machine backup request is initiated based on:

• Schedule defined in the backup policy.
• On-demand backup

Phoenix forwards the backup request to the agent.

Step 2

Phoenix agent verifies that the VSS service is running. The Phoenix agent requests the VSS service to create a snapshot. If the VSS service is not running, Phoenix agent starts the VSS service and instructs VSS to create a snapshot.

Druva recommends that you enable Backup (volume snapshot) under Hyper-V Integration Services. If the Backup (Volume snapshot) is enabled, the VSS service can create a snapshot without interrupting services on the virtual machine. 

Phoenix agent validates if snapshots are created successfully and initiates the backup job.
For  Windows Server 2008 and Windows Server 2008 R2 host:

• If Phoenix is backing up virtual machines that are stored on a clustered shared volume, then Phoenix can backup only one virtual machine at a time. 
• A hardware VSS provider is required if  you want Phoenix to create snapshots for multiple virtual machines simultaneously on a single host and run parallel backup jobs. For information on how to configure Phoenix so that it can use third party VSS providers, see How do I configure Phoenix to use third party VSS providers?.

Note: Integration Services are available for virtual machines with Windows guest OS. However, Microsoft provides Integration Services for certain Linux distributions also. For more information, see:

• Backup (volume snapshot) under Integration Services [External link to Microsoft TechNet article]
• Supported Linux and FreeBSD virtual machines for Hyper-V on Windows [External link to Microsoft TechNet article]

If integration services are not available for a virtual machine, Phoenix cannot take a snapshot and backup fails.

Step 3

Phoenix determines the type of backup. 

• If this is the first automatic backup, Phoenix performs a full backup. 
• For all subsequent backups, Phoenix performs an incremental backup. 

Step 4

Agent estimates the data for backup

Step 5

Agent backs up the data based on the VSS provided snapshot