When connecting Veeam to the vCenter infrastructure you must supply credentials which the Veeam Backup & Replication server will use when communicating with the vCenter server. The features that Veeam provides, such as backup, restore, replication, and SureBackup, interact with vSphere at a fundamental level.
Thus, certain permissions are required to take snapshots, create VMs, datastores, and resource groups. Because of this level of interaction, it is generally recommended that Veeam Backup & Replication use an account with full administrative permissions.
However, in some environments providing full administrative permissions is not desirable or allowed. For those environments, Veeam has identified the minimum permissions required for the various functions within the software. Please review the permissions required as defined in the Required Permissions document and configure the account used by Veeam Backup and Replication to meet these requirements.
You can also leverage security to restrict the view of the environment that a Veeam backup server can “see”. This can have multiple benefits beyond security in that it lowers the time required to parse the vCenter hierarchy and reduces to memory footprint required to cache this information. However, care must be taken when attempting to use this level of restriction, as some permissions must be provided at the very top of the vCenter tree.
For detailed description of accounts, rights and permissions required for Veeam Backup & Replication operation, you can refer to the Required Permissions document.