When a member of a business group requests a cloud machine, a reservation must be selected from the reservations that belong to the business group.
The reservation on which a machine is provisioned must satisfy the following criteria:
The reservation must be of the same platform type as the blueprint from which the machine was requested.
The reservation must be enabled.
The reservation must have capacity remaining in its machine quota or have an unlimited quota.
The allocated machine quota includes only machines that are powered on. For example, if a reservation has a quota of 50, and 40 machines have been provisioned but only 20 of them are powered on, the reservation’s quota is 40 percent allocated, not 80 percent.
The reservation must have the security groups specified in the machine request.
The reservation must be associated with a region that has the machine image specified in the blueprint.
For Amazon machines, the request specifies an availability zone and whether the machine is to be provisioned a subnet in a Virtual Private Cloud (VPC) or a in a non-VPC location. The reservation must match the network type (VPC or non-VPC).
If the cloud provider supports network selection and the blueprint has specific network settings, the reservation must have the same networks.
If the blueprint or reservation specifies a network profile for static IP address assignment, an IP address must be available to assign to the new machine.
If the blueprint specifies a reservation policy, the reservation must belong to that reservation policy.
Reservation policies are a way to guarantee that the selected reservation satisfies any additional requirements for provisioning machines from a specific blueprint. For example, if a blueprint uses a specific machine image, you can use reservation policies to limit provisioning to reservations associated with the regions that have the required image.
If no reservation is available that meets all of the selection criteria, provisioning fails.
If multiple reservations meet all of the criteria, the reservation from which to provision a requested machine is determined by the following logic:
Reservations with higher priority are selected over reservations with lower priority.
If multiple reservations have the same priority, the reservation with the lowest percentage of its machine quota allocated is selected.
If multiple reservations have the same priority and quota usage, machines are distributed among reservations in round-robin fashion.