I have some doubts about archive full backups to cloud with low bandwidth:
Background:
In our organization we want to change our monthly backups from tapes to cloud using Scale-Out Repositories with Azure Blob.
I upgraded our VB&R to 10 version so from the Backup Job I can configure GFS(we don't have "copy job" jobs). I want to kept 120 monthly backups (10 years) in Azure.
Currently our monthly backups to tape are around 7TB by month.
Our internet bandwidth is 100 Mbps so to upload files to internet is around 10-13 MBps
I created a new backup job for a single VM (100 GB) setting as repository our Scale-Out repo, the first Full Backup is 25GB and when it moved the files to capacity tier (Azure) it took 2 hours to move it.
My question is if we want to move our monthly backups to Azure will it move around 7 TB every month? or it can create full backups in azure and only move the blocks that were changed from previous monthly backups saved in azure?
If it needs to move every month 7 TB to azure at 10-13 MBps it will take 9-12 days to finish

Regards