To retrieve VM data blocks from a SAN LUN during backup, the backup proxy uses metadata about the layout of VM disks on the SAN.
Data backup in the Direct SAN access mode includes the following steps:
- The backup proxy sends a request to the ESX(i) host to locate the necessary VM on the datastore.
- The ESX(i) host locates the VM.
- Veeam Backup & Replication triggers VMware vSphere to create a VM snapshot.
- The ESX(i) host retrieves metadata about the layout of VM disks on the storage (physical addresses of data blocks).
- The ESX(i) host sends metadata to the backup proxy.
- The backup proxy uses metadata to copy VM data blocks directly from the source storage over the SAN.
- The backup proxy processes copied data blocks and sends them to the target.