VMware virtual machine backup workflow

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

In case of application-aware backup: 

1. Phoenix injects a temporary binary inside the VM to perform SQL app-aware backup
2. The binary is responsible for querying the SQL data and taking a VSS snapshot of the SQL data.

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 (Change Block Tracking) for incremental backups to identify the changed blocks.
• Tools Quiescing for an application-consistent snapshot. However, even without it, Phoenix can take a snapshot.

Step 4

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

Step 5

Backup proxy starts reading the virtual machine snapshot. 

Step 6

Step 7