Backup and DR Service uses VMware vSphere Storage APIs - Data Protection (formerly known as VMware vStorage APIs for Data Protection or VADP) to create backups of VMware VMs, placing these backups either in the snapshot pool of the backup/recovery appliance or in OnVault pools, or in both.
Backup and DR uses snapshots to incrementally backup data from your VMDKs at the VM level. After Backup and DR Service creates a backup of the current state of all VMDKs attached to an VM, you can use it to either:
Mount that data to create a new VMware VM. See Mount a VMware image.
Mount that data as a new disk(s) attached to a selected VM (either the source VM or a different physical host or VM). See Mount a VMware image.
Restore that data to either all or selected disks attached to the source VMware VM. See Restore a VMware VM.
Clone that data to either all or selected disks attached to a new target VMware VM. See Restore a VMware VM.
Backup and DR can be configured to store multiple copies of each snapshot across multiple locations using OnVault that writes backups to Cloud Storage, or StreamSnap that copies snapshots to a second backup/recovery appliance. Backup and DR uses automatic checksums to ensure the integrity of your data after each successful backup job.
How it works: Backup and DR VMware VM snapshots
Data backup with VMware VMs follows these steps:
The first successful snapshot of a VMware VM creates a snapshot of each virtual disk (VMDK). For each disk this is a full snapshot that contains all of the data on the virtual disk.
The second snapshot only contains any new data or modified data since the first snapshot. Data that hasn't changed since snapshot 1 isn't included. Instead, snapshot 2 contains references to snapshot 1 for any unchanged data.
Snapshot 3 contains any new or changed data since snapshot 2 but won't contain any unchanged data from snapshot 1 or 2. Instead, snapshot 3 contains references to blocks in snapshot 1 and snapshot 2 for any unchanged data.
This repeats for all subsequent snapshots of the VMware VM. Snapshots are always created based on the last successful snapshot taken by Backup and DR. If an additional virtual disk is added to the VMware VM, this disk is automatically included in the next snapshot of the VM. You can also use include/exclude rules to control which virtual disks are included in each backup. By default, all virtual disks are included in the Volume Inclusion Rule.
Data mount with VMware VM backups follows these steps:
Select the VMware VM and point in time that they want to work with.
Select if you want to mount to an existing host or VM, create a new VMware VM or restore the disks of the source VMware VM.
If creating a new VMware VM, select the location variables such as which vCenter, ESX host and datastore to be used.
Backup and DR uses snapshot technology to create new virtual disks from the backups. When these disks are created they are attached to the host or to the new or existing VMware VM. These virtual disks are writable, and can be migrated to physical disks via a VMware Storage VMotion task.
Backup storage location
When you create a backup plan and apply it to a VMware VM, the policies and profile specify where the backup is stored.
VMware VM-based backup data can be stored directly into Google Cloud Storage, via a Direct to OnVault template in the backup plan. This works for both on-premises and Google Cloud VMware Engine, though it is recommended to ensure sufficient bandwidth exists if you are using this feature. If bandwidth is limited, then a local snapshot policy is recommended, which retains a copy of the backup data for a user defined period of time, and in addition to the snapshot policy, additional OnVault policies can be enabled to store data for longer periods of time in Google Cloud Storage bucket(s).
OnVault backups can be stored in either one Cloud Storage multi-regional location, such as asia, or one Cloud Storage regional location, such as asia-south1. Each VM can have up to four OnVault policies, each specifying different Google Cloud Storage buckets, which could be different storage classes and different location types.
A multi-regional storage location provides the highest availability and resilience. A regional storage location gives you more control over the physical location of your data because you specify a single region.