Impact of Multiple Backup Applications on Performance
Previously Veeam Backup for Microsoft 365 recommended you to add auxiliary Azure AD applications to the product configuration for Microsoft 365 organizations added using modern app-only authentication. Such backup applications were intended to improve performance and minimize throttling from Microsoft 365 when backing up Microsoft SharePoint Online and Microsoft OneDrive for Business data.
Due to recent restrictions that were applied by Microsoft, Veeam Backup for Microsoft 365 invokes you to use a single Azure AD application when backing up data in your production SharePoint environment.
In large-scale environments, you can use multiple backup applications to perform the initial backup under the supervision of Veeam Customer Support specialists. For all subsequent incremental backups, a single Azure AD application should be used.
Consider that this recommendation was designed in collaboration of Veeam together with Microsoft.
Those users who already use multiple backup applications to back up Microsoft SharePoint Online and Microsoft OneDrive for Business data and do not experience performance degradation in their Microsoft 365 environments can continue further without any changes in the Veeam Backup for Microsoft 365 configuration.