Veeam Backup & Replication works with HP and NetApp storage products to create backups and replicas from storage snapshots in the following way. The backup/replica job:
- Analyzes which VMs in the job have disks on supported storage.
- Triggers a vSphere snapshot for all VMs located on the same storage volume. (As a part of a vSphere snapshot, Veeam’s application-aware processing of each VM is performed normally.)
- Triggers a snapshot of said storage volume once all VM snapshots have been created.
- Retrieves the CBT information for VM snapshots created on step 2.
- Immediately triggers the removal of the vSphere snapshots on the production VMs.
- Mounts the storage snapshot to one of the backup proxies connected into the storage fabric.
- Reads new and changed virtual disk data blocks directly from the storage snapshot and transports them to the backup repository or replica VM.
- Triggers the removal storage snapshot once all VMs have been backed up.
As the result, VMs run off snapshots for the shortest possible time, while jobs obtain data from VM snapshot files preserved in the storage snapshot. As the result, VM snapshots do not get a chance to grow large and can be committed very quickly without overloading production storage with extended merge procedure, as is the case with classic techniques for backing up from VM snapshots.