The Cloud Backup and Recovery Service now has a function that automatically increases the size of the vault as soon as the size of the vault is exceeded. The name of the function is “Auto Capacity Expansion” and can be adjusted directly within vault creation or afterwards.
Automatic adjustment of the CBR vault available

When activated, the size of the vault is automatically increased by a factor of 1.25 (25%). Please bear in mind that you are not paying for the size of the vault, but for the amount of backup data that is stored in the vault. The function is available for all regions and all backup types (EVS, ECS & SFS).
Additional information: A backup is also performed if the preset vault size would be exceeded by performing the backup. Only after the creation of the backup exceeding the vault size, no further backups can be created.