Backup copy job details
During the backup copying process, Veeam Backup & Replication does not simply copy a backup file from one backup repository to another. Instead, Veeam Backup & Replication retrieves data blocks necessary to create a restore point as of the latest point in time and copies this data to the cloud repository. This is the default behavior for a backup copy job and helps to reduce the required bandwidth to the target repository.
If the “Read the entire restore point from source instead of synthesizing it from increments” checkbox is checked, this behavior is changed which will negate the bandwidth savings.
The backup chain produced on the target backup repository is forever incremental: the first file in the chain is a full backup while all subsequent restore points are incremental.
For more detail on copy jobs, please see the user guide here:
https://helpcenter.veeam.com/docs/backup/vsphere/about_backup_copy.html?ver=100