When someone subscribes to a hosting plan, Business Manager assigns the subscription to a certain panels group and creates a hosting account on one of the panels from the group. You can define how Business Manager makes the panel choice by selecting one of the group settings:
To change the fill type for a panel group, click the Edit link for this group and choose a type from a drop-down menu.
Business Manager defines load of each panel using server weight. The server weight is a value that you assign to each hosting plan. This value refers to the number of resources a subscription to this plan is going to use on the panel sever, in terms of disk space, bandwidth, etc. For each Panel, you should assign a Maximum Server Weight. Configure this setting appropriate to how you plan to specify weights of your plans so you can be confident you will not be overselling your equipment - as each time Business Manager creates a hosting account on a panel, the weight of the corresponding plan subscription is added to the total weight of accounts already created on the server.
If you want to limit the load of certain panel, you can also restrict creating new hosting subscriptions on them. To do this, disable these panels. You are still able to perform all operations (suspend, activate, cancel, etc) with existing subscriptions on disabled panels. The control for disabling panels is located on the panel options page, to which you can navigate by clicking the Edit link for the panel.