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Druva Documentation

VMware virtual machine backup workflow

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

Phoenix performs backup on virtual machines based on the schedule defined in the backup policy, that virtual machine is a part of or an on-demand backup triggered from Phoenix Management Console. This involves the interaction of Phoenix components and VMware components.

The following diagram depicts the data flow at the time of backing up virtual machines.

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Virtual machine backup workflow

Step Operation

Step 1

Virtual machine backup request is initiated based on,

  • Schedule defined in the backup policy.
  • Manual backup

Phoenix forwards the backup request to the backup proxy pool.

  • Based on the load balancing algorithm, Phoenix automatically identifies the backup proxy that will run the backup request.
  • If the identified backup proxy is busy, the backup request is queued and initiated when the backup proxy becomes free.

Step 2

  • In an environment where virtual machines are deployed on ESXi hosts managed by vCenter server, backup proxy contacts vCenter Server to locate the virtual machine and obtains its configuration.
  • In an environment where virtual machines are deployed on standalone ESXi hosts, backup proxy contacts ESXi host to obtain the virtual machine configuration.

Step 3

The backup proxy queries the ESXi hypervisor or the vCenter server to create VM snapshots that contain VMDK files and the VMX files of the virtual machines.  Ensure that enough storage is available on the local datastore for the VM snapshot.

The backup proxy uses CBT and Tools Quiescing to create a virtual machine snapshot. For the first automatic backup, the backup proxy creates a snapshot of a full backup. For all subsequent backups, the backup proxy creates snapshots of the incremental backups. 

Step 4

Backup proxy establishes a VDDK connection to the VM snapshot using a transport mode to read the VM data. 

Reading encrypted VMDK through the NBD mode is not supported. The backup proxy can read encrypted VMDK disks either using NBDSSL or HotAdd. Here are the supported transport modes:

Backup proxy Virtual Machine Transport mode
Encrypted Encrypted HotAdd
Unencrypted Encrypted NBD-SSL
Encrypted Unencrypted HotAdd

Step 5

Backup proxy starts reading the virtual machine snapshot. 

Note: The backup proxy reads the VM snapshot on the local datastore.

Step 6

The backup proxy reads the virtual machine snapshot and prepares to send the backup data to Phoenix CloudCache (if configured) or Phoenix Cloud.

Step 7

Backup proxy transfers the backup data in a continuous stream to the Phoenix Cloud. Before transferring the data to the Phoenix Cloud, the backup proxy performs the de-duplication.

After the transfer completes, the backup proxy deletes the snapshot stored on the local datastore.