All XenServer users must have an RBAC role. In XenServer v6.2.0, you must first assign a role to the newly created user before they can use the account. Note that XenServer does not automatically assign a role to the newly created user. As a result, these accounts will not have any access to the XenServer pool until you assign them a role.
Assigning roles to users in XenServer v6.1.0 and earlier
In XenServer v6.1.0 and earlier, when new users are added, they are automatically assigned the Pool Administrator role. In XenServer Enterprise and higher, when you add new users, XenServer does not assign newly added user accounts roles automatically. You must assign roles to new accounts separately.
You can assign a user a different role by one of the following methods:
If, on separate occasions, an administrator indirectly applies multiple roles to a user (for example, by the user being a member of multiple groups), XenServer grants the user the permissions from the highest role to which he or she was assigned.